View source for Microsoft Outlook

{{Short description|Email and calendaring software}}
{{About|the desktop subscription software|the web platform|Outlook on the web|the email service|Outlook.com|}}

{{Use mdy dates|date=December 2023}}
{{Infobox software
| logo = File:Microsoft Outlook Icon (2025–present).svg
| logo caption = Microsoft Outlook app icon
| logo_size = 150px
| screenshot = Microsoft Outlook.png
| caption = An email inbox in Outlook (New UI, 365/Office 2024), running on [[Windows 11]]
| developer = [[Microsoft Corporation]]
| ver layout = stacked
| released = {{Start date and age|1997|01|16}}
| latest release version = {{Latest stable software release/Microsoft Office}}
| operating_system = [[Microsoft Windows|Windows]], [[macOS]], [[Android (operating system)|Android]], [[iOS]]
| genre = [[Personal information manager]]
| license = [[Trialware]]
| website = {{URL|https://outlook.office.com}}
}}
'''Microsoft Outlook''' is a [[personal information manager]] software system from [[Microsoft]], available as a part of the [[Microsoft 365]] software suite. Primarily popular as an [[email client]] for businesses, Outlook also includes functions such as [[Calendaring software|calendaring]], [[Time management#Software applications|task managing]], [[contact manager|contact managing]], [[note-taking]], [[Transaction log|journal logging]], [[Web navigation|web browsing]], and [[RSS]] [[News aggregator|news aggregation]].

Individuals can use Outlook as a [[Software|stand-alone application]]; organizations can deploy it as [[multi-user software]] (through [[Microsoft Exchange Server]] or [[SharePoint]]) for shared functions such as [[Email box|mailboxes]], [[Calendaring software|calendars]], [[Shared resource|folders]], [[data aggregation]] (i.e., SharePoint lists), and as [[Appointment scheduling software|appointment scheduling]] [[Mobile app|apps]].

Other than the paid software on [[Microsoft Windows|Windows]] and [[MacOS|Mac]] desktops described by this article, the Outlook name also covers several other current software:

* [[Outlook on the web]], formerly ''Outlook Web App'', a web version of Microsoft Outlook, included in Microsoft 365, [[Microsoft Exchange Server|Exchange Server]], and [[Exchange Online]] <small>(domain outlook.office365.com)</small>
* [[Outlook for Windows]], a free Outlook application that is preinstalled with Windows 10 and later
* [[Microsoft Outlook (mobile app)|Outlook Mobile]], a mobile app version of Outlook
* [[Outlook.com]], formerly ''Hotmail'', a free personal email service offered by Microsoft alongside a webmail client <small>(domain outlook.live.com)</small>

== Versions ==
Outlook replaced Microsoft's previous [[Calendaring software|scheduling]] and [[email client]]s, Schedule+ and [[Microsoft Exchange Server#Clients|Exchange Client]].

''Outlook 98'' and ''Outlook 2000'' offer two configurations:
*'''Internet Mail Only''' (aka '''IMO''' mode): A lighter application mode with specific emphasis on [[Post Office Protocol|POP3]] and [[Internet Message Access Protocol|IMAP]] accounts, including a lightweight [[Internet fax|fax application]].
*'''Corporate Work group''' (aka '''CW''' mode): A full [[MAPI]] client with specific emphasis on Microsoft Exchange accounts.

[[Software license|Perpetual]] versions of Microsoft Outlook include:

{| class="wikitable"
|-
! Name !! Version number<ref group="lower-roman">The version numbers follows the Office numbers.</ref>!! Release date<ref>{{cite web|url=http://support.microsoft.com/lifecycle/search/default.aspx?sort=PN&alpha=outlook&Filter=FilterNO|title=Microsoft Outlook Life-cycle Information|access-date=October 23, 2011|archive-date=March 1, 2013|archive-url=https://web.archive.org/web/20130301063727/http://support.microsoft.com/lifecycle/search/default.aspx?sort=PN&alpha=outlook&Filter=FilterNO|url-status=live}}</ref> !! Notes
|-
! Outlook 97
| 8.0
| January 16, 1997
| Included in [[Office 97]] and bundled with [[Microsoft Exchange Server|Exchange Server]] 5.0 and 5.5. This was a renamed and slightly upgraded version of the Microsoft Exchange client.
|-
! Outlook 98
| 8.5
| June 21, 1998
| Freely distributed with books and magazines to cope with the newest Internet standards such as [[HTML email]].<ref name=":0">{{Cite web |last=Singh |first=Rohit |date=June 3, 2021 |title=The Ultimate Guide to Convert Outlook OST to PST File |url=https://www.cigatisolutions.com/blog/convert-ost-to-pst-file/ |access-date= |website=Cigati Solutions |archive-date=January 4, 2023 |archive-url=https://web.archive.org/web/20230104185959/https://www.cigatisolutions.com/blog/convert-ost-to-pst-file/ |url-status=live }}</ref> Outlook 98 setup was based on [[Active Setup]] which also installed [[Internet Explorer 4]].<ref>{{Cite web|url=http://support.microsoft.com/kb/277552|title=OL98: How to Troubleshoot Active Setup Problems in Windows 98, 98 SE or ME|date=January 29, 2007|website=Support|archive-url=https://web.archive.org/web/20070316000058/http://support.microsoft.com/kb/277552|archive-date=March 16, 2007|access-date=June 18, 2019|edition=3.1}}</ref>
|-
! Outlook 2000
| 9.0
| June 27, 1999
| Included in [[Office 2000]] and bundled with Exchange 2000 Server
|-
! Outlook 2002
| 10
| May 31, 2001
| Included in [[Office XP]]
|-
! Outlook 2003
| 11
| November 20, 2003
| Included in [[Office 2003]] (incl. Standard Edition for Students and Teachers) and bundled with Exchange Server 2003
|-
! Outlook 2007 
| 12
| January 27, 2007
| Included in [[Office 2007]], except Office Home and Student edition
|-
! Outlook 2010
| 14
| July 15, 2010
| Included in [[Office 2010]] Home and Business, Standard, Professional and Professional Plus
|-
! Outlook 2011 for Mac
| 14
| October 26, 2010
| Included in [[Microsoft Office for Mac 2011|Office for Mac 2011]] Home and Business
|-
! Outlook 2013
| 15
| January 29, 2013
| Included in [[Microsoft Office 2013|Office 2013]], except Home & Student edition
|-
! Outlook for Mac
| 15.3
| October 31, 2014
| Included in [[Office 365]], except some{{which|date=November 2014}} commercial editions
|-
! Outlook 2016
| 16
| September 22, 2015
| Included in [[Microsoft Office 2016|Office 2016]] and Office 365
|-
! Outlook 2016 for Mac
| 15.12
| September 25, 2015
| Included in Office 2016 and Office 365
|-
! Outlook 2019
| 16
| September 24, 2018
| Included in [[Microsoft Office 2019|Office 2019]] and Office 365
|-
! Outlook 2019 for Mac
| 16.17
| September 24, 2018
| Included in Office 2019 and Office 365
|-
! Outlook for Phones & Tablets
| 1.3
| 2015
| Included in Office 365, except some{{which|date=November 2014}} commercial editions
Includes [[iOS]] and [[Android (operating system)|Android]] support
|-
|}

=== Microsoft Outlook ===

Microsoft Outlook is an email and personal information manager software primarily used in professional settings. As part of the [[Microsoft Office|Microsoft Office suite]], it offers email management, contact storage, calendar scheduling, and task tracking. Outlook can function independently or as part of a larger Microsoft ecosystem, including integration with [[SharePoint]] for file sharing. While it stores email data locally for offline access, newer versions restrict link opening to Microsoft's own browsers.<ref>{{Cite web |url=https://www.theverge.com/2023/5/3/23709297/microsoft-edge-force-outlook-teams-web-links-open |title=Microsoft is forcing Outlook and Teams to open links in Edge, and IT admins are angry |date=May 3, 2023 |access-date=May 4, 2023 |archive-date=May 4, 2023 |archive-url=https://web.archive.org/web/20230504190044/https://www.theverge.com/2023/5/3/23709297/microsoft-edge-force-outlook-teams-web-links-open |url-status=live }}</ref><ref name=":0" />{{trivia|section|date=May 2019}}

Privacy is severely degraded in the latest versions, as the new Outlook sends passwords, mails and other data to Microsoft.<ref>{{Cite web |url=https://mailbox.org/en/post/warning-new-outlook-sends-passwords-mails-and-other-data-to-microsoft |title=Warning: New Outlook sends passwords, mails and other data to Microsoft |date=November 10, 2023 |access-date=November 15, 2023 |archive-date=November 14, 2023 |archive-url=https://web.archive.org/web/20231114050933/https://mailbox.org/en/post/warning-new-outlook-sends-passwords-mails-and-other-data-to-microsoft |url-status=live }}</ref><ref>{{Cite web |url=https://www.heise.de/news/Microsoft-krallt-sich-Zugangsdaten-Achtung-vorm-neuen-Outlook-9357691.html |title=Microsoft krallt sich Zugangsdaten: Achtung vor dem neuen Outlook |date=November 9, 2023 |access-date=November 15, 2023 |archive-date=November 15, 2023 |archive-url=https://web.archive.org/web/20231115174832/https://www.heise.de/news/Microsoft-krallt-sich-Zugangsdaten-Achtung-vorm-neuen-Outlook-9357691.html |url-status=live }}</ref>

==== Outlook 2002 ====
Outlook 2002 introduced these new features:<ref name="Outlook2002ProductGuide">{{cite web |url=https://www.microsoft.com:80/office/outlook/evaluation/OutlkPG.doc |title=Microsoft Outlook 2002 Product Guide |date=May 30, 2001 |publisher=[[Microsoft]] |format=DOC |archive-url=https://web.archive.org/web/20030207192651/http://www.microsoft.com/office/outlook/evaluation/OutlkPG.doc |archive-date=February 7, 2003 |access-date=December 31, 2017 |url-status=dead }}</ref>
*[[Autocomplete]] for [[email address]]es
* Colored categories for calendar items
* Group schedules
*[[Hyperlink]] support in email subject lines
* Native support for [[Outlook.com]] (formerly Hotmail)
* Improved search functionality, including the ability to stop a search and resume it later
* [[Lunar calendar]] support
*[[MSN Messenger]] integration
* Performance improvements<ref name="Outlook2002PerformanceTuning">{{cite web |url=https://www.microsoft.com:80/office/outlook/evaluation/perform.doc |title=Microsoft Outlook 2002 Performance Tuning |date=June 7, 2001 |publisher=[[Microsoft]] |format=DOC |archive-url=https://web.archive.org/web/20031004211956/http://www.microsoft.com/office/outlook/evaluation/perform.doc |archive-date=October 4, 2003 |access-date=December 31, 2017 |url-status=dead }}</ref>
* Preview pane improvements, including the ability to: 
**open hyperlinks;
**respond to meeting requests; and 
**display email properties without opening a message
* Reminder window that consolidates all reminders for appointments and tasks in a single view
* [[Retention period|Retention policies]] for documents and email
* Security improvements, including the automatic blocking of potentially unsafe attachments and of programmatic access to information in Outlook:
** SP1 introduced the ability to view all non-[[digital signature|digitally signed]] email or [[plaintext|unencrypted]] email as [[plain text]];<ref name="Outlook2002SP1PlainText">{{cite web |url=http://support.microsoft.com:80/kb/307594 |title=OL2002: Users Can Read Nonsecure E-mail as Plain Text |publisher=[[Microsoft]] |work=Support |archive-url=https://web.archive.org/web/20041020204339/http://support.microsoft.com/kb/307594 |archive-date=October 20, 2004 |access-date=December 31, 2017 |url-status=dead }}</ref>
** SP2 allows users to—through the [[Windows Registry|Registry]]—prevent the addition of new email accounts or the creation of new [[Personal Storage Table]]s;<ref name="OfficeXPSP2OutlookCh">{{cite web |url=http://www.itprotoday.com/microsoft-exchange/office-xp-sp2-brings-changes-outlook |title=Office XP SP2 Brings Changes to Outlook |last=Mosher |first=Sue |date=August 26, 2002 |publisher=[[Penton (company)|Penton]] |work=Windows IT Pro |archive-url=https://archive.today/20180101012444/http://www.itprotoday.com/microsoft-exchange/office-xp-sp2-brings-changes-outlook |archive-date=January 1, 2018 |access-date=January 1, 2018}}</ref>
** SP3 updates the object model guard security for applications that access messages and other items.<ref name="Outlook2003SP3">{{cite web |url=http://www.itprotoday.com/microsoft-exchange/tighter-security-outlook-2002-sp3 |title=Tighter Security in Outlook 2002 SP2 |last=Mosher |first=Sue |date=March 25, 2004 |publisher=[[Penton (company)|Penton]] |work=Windows IT Pro |archive-url=https://archive.today/20180101013323/http://www.itprotoday.com/microsoft-exchange/tighter-security-outlook-2002-sp3 |archive-date=January 1, 2018 |access-date=January 1, 2018}}</ref>
* [[Smart tag (Microsoft)|Smart tag]]s when [[Microsoft Word|Word]] is configured as the default email editor. This option was available only when the versions of Outlook and Word were the same, i.e. both were 2002.

==== Outlook 2003 ====
Outlook 2003 introduced these new features:<ref name="Office2003ProductGuide">{{cite web|url=https://download.microsoft.com/download/0/f/1/0f1d5b1f-53bc-47c3-bf6f-ac6d67cf9766/office2003guide.doc |title=Microsoft Office 2003 Editions Product Guide |date=September 2003 |publisher=[[Microsoft]] |format=DOC |archive-url=https://web.archive.org/web/20051104045819/http://download.microsoft.com/download/0/f/1/0f1d5b1f-53bc-47c3-bf6f-ac6d67cf9766/Office2003Guide.doc |archive-date=November 4, 2005 |access-date=March 5, 2017 |url-status=dead }}</ref>
*[[Autocomplete]] suggestions for a single character
*[[Cache (computing)|Cached]] Exchange mode
* Colored (quick) flags
* Desktop Alert
* [[Email filtering]] to combat [[email spam|spam]]
** Images in [[HTML email|HTML mail]] are blocked by default to prevent spammers from determining whether an email address is active via [[web beacon]];<ref name="AvoidSpam">{{cite web |url=http://www.techrepublic.com:80/blog/microsoft-office/how-do-i-avoid-e-mail-spam-using-outlook-tools |title=How do I... Avoid e-mail spam using Outlook tools? |last=Harkins |first=Susan |date=April 22, 2008 |publisher=[[CBS Interactive]] |work=[[TechRepublic]] |archive-url=https://web.archive.org/web/20131224202911/http://www.techrepublic.com/blog/microsoft-office/how-do-i-avoid-e-mail-spam-using-outlook-tools |archive-date=December 24, 2013 |access-date=January 2, 2018 |url-status=dead }}</ref>
** SP1 introduced the ability to block email based on [[country code top-level domain]]s;<ref name="Office2003SP1IW">{{cite web |url=https://www.infoworld.com/article/2665648/security/you-have-nothing-to-fear-from-office-2003-sp1.html |title=You have nothing to fear from Office 2003 SP1 |last=Rist |first=Oliver |date=August 20, 2004 |publisher=[[International Data Group|IDG]] |work=[[InfoWorld]] |archive-url=https://web.archive.org/web/20171231232032/https://www.infoworld.com/article/2665648/security/you-have-nothing-to-fear-from-office-2003-sp1.html |archive-date=December 31, 2017 |access-date=December 31, 2017}}</ref>
** SP2 introduced [[phishing#Anti-phishing|anti-phishing]] functionality that automatically disables hyperlinks present in spam<ref name="Outlook2003SP2PhishingFilter">{{cite web |url=http://searchexchange.techtarget.com/tip/Microsoft-Office-2003-SP2s-antiphishing-filter-for-Outlook |title=Microsoft Office 2003 SP2's antiphishing filter for Outlook |last=Yegulalp |first=Serdar |publisher=[[TechTarget]] |work=SearchExchange |access-date=December 31, 2017 |archive-date=January 1, 2018 |archive-url=https://web.archive.org/web/20180101082418/http://searchexchange.techtarget.com/tip/Microsoft-Office-2003-SP2s-antiphishing-filter-for-Outlook |url-status=dead }}</ref>
* Expandable [[distribution list]]s
* [[Information rights management]]
* Intrinsic support for [[tablet PC]] functionality (e.g., [[handwriting recognition]])
* Reading pane
* [[Virtual folder|Search folders]]
* [[Unicode]] support

==== Outlook 2007 ====
[[File:Outlook 07.png|thumb|The main Outlook 2007 interface with its [[menu (computing)|menu]]s and [[toolbar]]s]]
[[File:Outlook2007SMS.png|thumb|right|Outlook 2007 with options for text message composition. The left-hand side depicts a preview of how the message will appear on the recipient's phone.]]
Features that debuted in Outlook 2007 include:<ref name="Outlook2007NewFeatures">{{cite web |url=http://office.microsoft.com:80/en-us/help/HA100743061033.aspx |title=What's new in Microsoft Office Outlook 2007 |publisher=[[Microsoft]] |work=Support |archive-url=https://web.archive.org/web/20100123042631/http://office.microsoft.com/en-us/help/HA100743061033.aspx |archive-date=January 23, 2010 |access-date=January 3, 2018 |url-status=dead }}</ref>
* Attachment preview, with which the contents of attachments can be previewed before opening
** Supported [[file type]]s include [[Microsoft Excel|Excel]], [[Microsoft PowerPoint|PowerPoint]], [[Microsoft Visio|Visio]], and [[Microsoft Word|Word]] files. If Outlook 2007 is installed on [[Windows Vista]], then audio and video files can be previewed. If a compatible [[list of PDF software|PDF reader]] such as [[Adobe Acrobat]] [[Adobe Acrobat version history#Acrobat|8.1]] is installed, [[PDF]] files can also be previewed.<ref name="Outlook2007vsOutlook2003">{{cite web |url=http://www.itprotoday.com/microsoft-exchange/outlook-2007-vs-outlook-2003 |title=Outlook 2007 vs. Outlook 2003 |last=Bruzzese J. |first=Peter |date=February 4, 2008 |publisher=[[Penton (company)|Penton]] |work=Windows IT Pro |archive-url=https://web.archive.org/web/20180103041458/http://www.itprotoday.com/microsoft-exchange/outlook-2007-vs-outlook-2003 |archive-date=January 3, 2018 |access-date=January 3, 2018}}</ref>
* Auto Account Setup, which allows users to enter a username and password for an email account without entering a server name, port number, or other information
* Calendar sharing improvements including the ability to export a calendar as an [[HTML]] file—for viewing by users without Outlook—and the ability to publish calendars to an external service (e.g., [[Office Web Apps]]) with an online provider (e.g., [[Microsoft account]])
* Colored categories with support for user roaming, which replace colored (quick) flags introduced in Outlook 2003<ref name="Outlook2007ModifiedFunctionality">{{cite web |url=http://office.microsoft.com:80/en-us/outlook/HA100926831033.aspx |title=Discontinued features and modified functionality in Outlook 2007 |publisher=[[Microsoft]] |work=Support |archive-url=https://web.archive.org/web/20091227234725/http://office.microsoft.com/en-us/outlook/HA100926831033.aspx |archive-date=December 27, 2009 |access-date=January 3, 2018 |url-status=dead }}</ref>
* Improved email spam filtering and anti-phishing features
**[[Postmark]] intends to reduce [[Spamming|spam]] by making it difficult and time-consuming to send it
* Information rights management improvements with [[Windows Rights Management Services]] and managed policy compliance integration with Exchange Server 2007
* [[Japanese language|Japanese]] [[Kanji#Readings|yomi reading]] name support for contacts
* Multiple calendars can be overlaid with one another to assess details such as potential scheduling conflicts
* [[Ribbon (computing)|Ribbon]] (Office Fluent) interface
* Outlook Mobile Service support, which allowed multimedia and [[SMS]] [[text messaging|text message]]s to be sent directly to [[mobile phone]]s<ref name="OutlookMobileService">{{cite web |url=https://blogs.msdn.microsoft.com/deva/2008/04/09/outlook-mobile-service-how-it-works-advantages-features/ |title=Outlook Mobile Service - How it works? Advantages? Features? |date=April 9, 2008 |publisher=[[Microsoft]] |work=[[Microsoft Developer Network|MSDN]] |archive-url=https://web.archive.org/web/20180102234027/https://blogs.msdn.microsoft.com/deva/2008/04/09/outlook-mobile-service-how-it-works-advantages-features/ |archive-date=January 2, 2018 |access-date=January 3, 2018}}</ref>
* [[Incremental search|Instant search]] through [[Windows Search]], an [[search engine indexing|index]]-based [[desktop search]] platform
** Instant search functionality is also available in Outlook 2002 and Outlook 2003 if these versions are installed alongside Windows Search<ref name="WindowsDesktopSearchOutlook">{{cite web |url=http://searchexchange.techtarget.com/tutorial/How-Windows-Desktop-Search-works-in-Microsoft-Outlook-2007 |title=How Windows Desktop Search works in Microsoft Outlook 2007 |last=Posey |first=Brian |date=April 21, 2009 |publisher=[[TechTarget]] |work=SearchExchange |archive-url=https://web.archive.org/web/20100927034333/http://searchexchange.techtarget.com/tutorial/How-Windows-Desktop-Search-works-in-Microsoft-Outlook-2007 |archive-date=September 27, 2010 |access-date=January 3, 2017 |url-status=dead }}</ref>
* Integrated [[RSS]] aggregation
* Support for [[Windows SideShow]] with the introduction of a calendar [[Microsoft Gadgets#Device gadgets and Windows Sideshow|gadget]]<ref name="Outlook2007Platform">{{cite web |url=https://msdn.microsoft.com/en-us/library/cc513842(v=office.12).aspx |title=Chapter 2: Outlook as a Platform |last2=Gregg |first2=Ryan |last1=Byrne |first1=Randy |date=2007 |publisher=[[Microsoft]] |work=[[Microsoft Developer Network|MSDN]] |archive-url=https://web.archive.org/web/20180103054335/https://msdn.microsoft.com/en-us/library/cc513842(v=office.12).aspx |archive-date=January 3, 2018 |access-date=January 3, 2018}}</ref>
*[[Time management|To-Do]] Bar that consolidates calendar information, flagged email, and tasks from [[Microsoft OneNote|OneNote]] 2007, Outlook 2007, [[Microsoft Project|Project]] 2007, and [[SharePoint|Windows SharePoint Services]] 3.0 [[website]]s within a central location.
* The ability to export items as PDF or [[Open XML Paper Specification|XPS]] files
* [[Unified messaging]] support with Exchange Server 2007, including features such as [[Missed call|missed-call]] notifications, and [[voicemail]] with voicemail preview and [[Windows Media Player]]<ref name="Outlook2007Platform"/>
* Word 2007 replaces [[Internet Explorer]] as the default viewer for [[HTML email]],<ref name="Outlook2007ModifiedFunctionality"/> and becomes the default email editor in this and all subsequent versions.

==== Outlook 2010 ====
[[File:Outlook 2010 box.jpg|thumb|Outlook 2010 in a retail box]]
Features that debuted in Outlook 2010 include:<ref name="Outlook2010NewFeatures">{{cite web |url=https://support.office.com/en-us/article/What-s-new-in-Microsoft-Outlook-2010-18c53bbe-8280-4fdd-b3f1-198adc57fc86 |title=What's new in Microsoft Outlook 2010 |publisher=[[Microsoft]] |work=Support |archive-url=https://web.archive.org/web/20160311132543/https://support.office.com/en-us/article/What-s-new-in-Microsoft-Outlook-2010-18c53bbe-8280-4fdd-b3f1-198adc57fc86 |archive-date=March 11, 2016 |access-date=January 3, 2017 |url-status=dead }}</ref>
* Additional [[command-line interface|command-line]] switches
* An improved conversation view that groups messages based on different criteria regardless of originating folders
*[[Internet Message Access Protocol|IMAP]] messages are sent to the Deleted Items folder, eliminating the need to mark messages for future deletion
* Notification when an email is about to be sent without a subject
* Quick Steps, individual collections of commands that allow users to perform multiple actions simultaneously
*[[Ribbon (computing)|Ribbon]] interface in all views
* Search Tools contextual tab on the ribbon that appears when performing searches and that includes basic or advanced criteria filters
* Social Connector to connect to various [[social network]]s and aggregate appointments, contacts, communication history, and file attachments
* Spell check-in additional areas of the user interface
* Support for multiple Exchange accounts in a single Outlook profile
* The ability to schedule a meeting with a contact by replying to an email message
* To-Do Bar enhancements including visual indicators for conflicts and unanswered meeting requests
*[[Voicemail]] transcripts for [[Unified messaging|Unified Messaging]] communications
* [[Zooming user interface]] for calendar and mail views

==== Outlook 2013 ====
Features that debuted in Outlook 2013, which was released on January 29, 2013, include:
*[[Email attachment|Attachment]] reminder
*[[Exchange ActiveSync]] (EAS)
* Add-in resiliency
*[[Cache (computing)|Cached]] Exchange mode improvements
*[[Internet Message Access Protocol|IMAP]] improvements
* Outlook [[data file]] ([[Personal Storage Table|.ost]]) [[Data compression|compression]]
* People hub
* Startup performance improvements

==== Outlook 2016 ====
Features that debuted in Outlook 2016 include:<ref>{{cite web|url=https://support.office.com/en-us/article/What-s-new-in-Outlook-2016-for-Windows-51c81e7a-de25-4a34-a7fe-bd79f8e48647?ui=en-US&rs=en-US&ad=US|title=What's new in Outlook 2016 for Windows|date=June 30, 2023|access-date=November 19, 2015|archive-date=April 15, 2017|archive-url=https://web.archive.org/web/20170415235011/https://support.office.com/en-us/article/What-s-new-in-Outlook-2016-for-Windows-51c81e7a-de25-4a34-a7fe-bd79f8e48647?ui=en-US&rs=en-US&ad=US|url-status=live}}</ref>
*[[Email attachment|Attachment]] link to [[Cloud computing|cloud resource]]
* Groups redesign
* Search cloud
* Clutter folder
*[[Email address internationalization|Email Address Internationalization]]
*[[Scalable Vector Graphics]]

==== Outlook 2019 ====
Features that debuted in Outlook 2019 include:<ref>{{cite web|url=https://support.office.com/en-us/article/what-s-new-in-outlook-2019-for-windows-0c64df36-0908-4ff6-a7fc-573a62800525|title=What's new in Outlook 2019|access-date=April 22, 2020|archive-date=November 12, 2020|archive-url=https://web.archive.org/web/20201112022940/https://support.microsoft.com/en-us/office/what-s-new-in-outlook-2019-for-windows-0c64df36-0908-4ff6-a7fc-573a62800525?ui=en-us&rs=en-us&ad=us|url-status=live}}</ref>
* Focused Inbox
* Add multiple [[time zone]]s
* Listen to your emails
* Easier email sorting
* Automatic download of [[Microsoft OneDrive|cloud attachments]]
* True Dark Mode (version 1907 onward)

==== Outlook 2024 ====

* Improved search for email, calendars, and contacts
* Send more accessible emails
* More options for meeting creation
* Reply to an email with a reaction

=== Macintosh ===
[[File:Outlook for macOS with new UI.png|thumb|Outlook for Mac with the new UI applied]]
Microsoft made several versions of Outlook for older Mac computers, but only for email accounts on specific company servers ([[Microsoft Exchange Server|Exchange]]). It was not included as part of the regular Microsoft Office package for Mac.

[[Microsoft Entourage]] was Microsoft's email app for Mac. It was similar to Outlook but didn't work well with Exchange email at first. Over time, it got better at handling Exchange, but it was always a different program than Outlook.

[[File:Microsoft Outlook 2011.png|thumb|Microsoft Outlook for Mac 2011]]
Entourage was replaced by Outlook for Mac 2011, which features greater compatibility and parity with Outlook for Windows than Entourage offered. It is the first native version of Outlook for [[macOS]].

Outlook 2011 initially supported Mac OS X's [[iSync|Sync Services]] only for contacts, not events, tasks or notes. It also does not have a Project Manager equivalent to that in Entourage.<ref>{{cite web | url=https://www.macworld.com/reviews/product/671493/review/outlook_for_mac_2011.html | title=Microsoft Outlook for Mac 2011 | last=Welsh | first=John C. | work=[[Macworld]] | publisher=[[International Data Group|IDG]] | date=October 1, 2010 | access-date=November 7, 2010 | archive-date=August 15, 2016 | archive-url=https://web.archive.org/web/20160815102237/http://www.macworld.com/article/1154484/web-apps/outlook2011mac.html | url-status=dead }}</ref> With [[Service pack|Service Pack]] 1 (v 14.1.0), published on April 12, 2011, Outlook can now sync calendar, notes and tasks with Exchange 2007 and Exchange 2010.

On October 31, 2014, [[Microsoft]] released Outlook for Mac (v15.3 build 141024) with [[Office 365]] (a [[software as a service]] licensing program that makes Office programs available as soon as they are developed). Outlook for Mac 15.3 improves upon its predecessors with:<ref name="outlook-for-mac-15.3" />
* Better performance and reliability as a result of a new threading model and database improvements.
* A new modern user interface with improved scrolling and agility when switching between Ribbon tabs.
* Online archive support for searching Exchange (online or on-premises) archived mail.
* Master Category List support and enhancements delivering access to category lists (name and color) and sync between Mac, Microsoft Windows and OWA clients.
* Office 365 push email support for real-time email delivery.
* Faster first-run and email download experience with improved Exchange Web Services syncing.<ref name="outlook-for-mac-15.3">{{cite web | url=http://blogs.office.com/2014/10/31/new-outlook-mac-available-office-365-customers/ | title=New Outlook for Mac available to Office 365 | work=Office Blogs | date=October 31, 2014 | publisher=[[Microsoft]] | access-date=November 1, 2014 | archive-date=November 3, 2014 | archive-url=https://web.archive.org/web/20141103044646/http://blogs.office.com/2014/10/31/new-outlook-mac-available-office-365-customers/ | url-status=live }}</ref>
The [https://support.microsoft.com/en-us/office/the-new-outlook-for-mac-6283be54-e74d-434e-babb-b70cefc77439 "New Outlook for Mac" client], included with version 16.42 and above, became available for "Early Insider" testers in the fall of 2019, with a public "Insider" debut in October 2020.<ref>{{Cite web|last=TimDavenport|title=Release notes for Office for Mac - Office release notes|url=https://docs.microsoft.com/en-us/officeupdates/release-notes-office-for-mac|access-date=April 13, 2021|website=docs.microsoft.com|language=en-us|archive-date=April 16, 2021|archive-url=https://web.archive.org/web/20210416202046/https://docs.microsoft.com/en-us/officeupdates/release-notes-office-for-mac|url-status=live}}</ref><ref>{{Cite web|last=Warren|first=Tom|date=September 22, 2020|title=Microsoft's new Outlook for Mac design launches in October|url=https://www.theverge.com/2020/9/22/21448985/microsoft-outlook-for-mac-new-design-october-release|access-date=April 13, 2021|website=The Verge|language=en|archive-date=April 30, 2021|archive-url=https://web.archive.org/web/20210430100622/https://www.theverge.com/2020/9/22/21448985/microsoft-outlook-for-mac-new-design-october-release|url-status=live}}</ref> It requires macOS 10.14 or greater and introduces a redesigned interface with significantly changed internals, including native search within the client that no longer depends on macOS [[Spotlight (software)|Spotlight]].<ref>{{Cite web|date=September 18, 2020|title=The new Outlook for Mac - Under the Hood|url=https://techcommunity.microsoft.com/t5/video-hub/the-new-outlook-for-mac-under-the-hood/m-p/1681528#M122|access-date=April 13, 2021|website=TECHCOMMUNITY.MICROSOFT.COM|language=en|archive-date=April 13, 2021|archive-url=https://web.archive.org/web/20210413183208/https://techcommunity.microsoft.com/t5/video-hub/the-new-outlook-for-mac-under-the-hood/m-p/1681528#M122|url-status=live}}</ref> Some Outlook features are still missing from the New Outlook client as it continues in development.<ref>{{Cite web|title=The new Outlook for Mac|url=https://support.microsoft.com/en-us/office/the-new-outlook-for-mac-6283be54-e74d-434e-babb-b70cefc77439|access-date=April 13, 2021|website=support.microsoft.com|language=en-US|archive-date=January 22, 2021|archive-url=https://web.archive.org/web/20210122005236/https://support.microsoft.com/en-us/office/the-new-outlook-for-mac-6283be54-e74d-434e-babb-b70cefc77439|url-status=live}}</ref>

To date, the Macintosh client has never had the capability of syncing Contact Groups/Personal Distribution Lists from Exchange, Microsoft 365 or Outlook.com accounts, something that the Windows and web clients have always supported.<ref>{{Cite web|title=Sync basics - what you can and cannot sync|url=https://support.microsoft.com/en-us/office/sync-basics-what-you-can-and-cannot-sync-5537d587-4930-4ac2-b044-3568509b1294|access-date=April 13, 2021|website=support.microsoft.com|language=en-US|archive-date=April 13, 2021|archive-url=https://web.archive.org/web/20210413181700/https://support.microsoft.com/en-us/office/sync-basics-what-you-can-and-cannot-sync-5537d587-4930-4ac2-b044-3568509b1294|url-status=live}}</ref> A UserVoice post created in December 2019 suggesting that the missing functionality be added has shown a "Planned" tag since October 2020.<ref>{{Cite web|last=Roy|first=Thomas|title=Support for contact lists (not contact groups!)|url=https://outlook.uservoice.com/forums/924856-the-new-outlook-for-mac/suggestions/39205405-support-for-contact-lists-not-contact-groups|access-date=April 13, 2021|website=Got an idea?|language=en|archive-date=April 13, 2021|archive-url=https://web.archive.org/web/20210413181701/https://outlook.uservoice.com/forums/924856-the-new-outlook-for-mac/suggestions/39205405-support-for-contact-lists-not-contact-groups|url-status=dead}}</ref>

In March 2023, Microsoft announced that Outlook for Mac will be available for free. This means that users no longer need a Microsoft 365 subscription or an Office licence to use the program.<ref>{{Cite web |last=Warren |first=Tom |date=March 6, 2023 |title=Microsoft makes Outlook for Mac free to use |url=https://www.theverge.com/2023/3/6/23626922/microsoft-outlook-mac-free-app |access-date=March 7, 2023 |website=The Verge |language=en-US |archive-date=March 6, 2023 |archive-url=https://web.archive.org/web/20230306234404/https://www.theverge.com/2023/3/6/23626922/microsoft-outlook-mac-free-app |url-status=live }}</ref>

=== Phones and tablets ===
First released in April 2014 by the [[venture capital]]-backed [[startup company|startup]] [[Acompli]], the company was acquired by [[Microsoft]] in December 2014. On January 29, 2015, Acompli was re-branded as Outlook Mobile—sharing its name with the Microsoft Outlook desktop [[personal information manager]] and [[Outlook.com]] email service.<ref name=verge-outlookmobile>{{cite web|title=Microsoft rebrands Acompli as Outlook for iOS and Android|url=https://www.theverge.com/2015/1/29/7936081/microsoft-outlook-app-ios-android-features|website=The Verge|date=January 29, 2015|access-date=January 31, 2015|archive-date=January 16, 2021|archive-url=https://web.archive.org/web/20210116125247/https://www.theverge.com/2015/1/29/7936081/microsoft-outlook-app-ios-android-features|url-status=live}}</ref> In January 2015, [[Microsoft]] released Outlook for phones and for tablets (v1.3 build) with [[Office 365]].<ref>Compare:
{{cite web
 | url= http://blogs.microsoft.com/blog/2015/01/29/office-everywhere-great-news-office-ios-android/
 | title= Office on iOS and Android
 | work= Office Blogs
 | date= January 29, 2015
 | publisher= [[Microsoft]]
 | access-date= January 11, 2015
 | archive-date= January 29, 2015
 | archive-url= https://web.archive.org/web/20150129170220/http://blogs.microsoft.com/blog/2015/01/29/office-everywhere-great-news-office-ios-android/
 | url-status= live
 }}</ref> This was the first Outlook for these platforms with email, calendar, and contacts.

On February 4, 2015, Microsoft acquired [[Sunrise Calendar]];<ref name=PCWorld>{{cite web|last=Miners|first=Zach|title=Microsoft reportedly buying slick calendar app Sunrise to bolster productivity push|url=http://www.pcworld.com/article/2880272/microsoft-said-to-acquire-calendar-app-sunrise-for-north-of-100-million.html|newspaper=[[PC World]]|date=February 4, 2015|access-date=April 13, 2020|archive-date=September 30, 2020|archive-url=https://web.archive.org/web/20200930200912/https://www.pcworld.com/article/2880272/microsoft-said-to-acquire-calendar-app-sunrise-for-north-of-100-million.html|url-status=live}}</ref> on September 13, 2016, Sunrise ceased to operate, and an update was released to Outlook Mobile that contained enhancements to its calendar functions.<ref>{{cite web|last=Warren|first=Tom|title=Microsoft isn't killing the Sunrise calendar app just yet|url=https://www.theverge.com/2016/9/1/12746910/microsoft-sunrise-shut-down-delayed|website=[[The Verge]]|date=September 1, 2016|access-date=April 13, 2020|archive-date=November 8, 2020|archive-url=https://web.archive.org/web/20201108123022/http://www.theverge.com/2016/9/1/12746910/microsoft-sunrise-shut-down-delayed|url-status=live}}</ref><ref name="verge-sunrisedelay">{{cite web|title=Microsoft Outlook's mobile app just added Sunrise's best features|url=https://www.theverge.com/2016/9/13/12895358/microsoft-outlook-sunrise-app-merger|website=The Verge|date=September 13, 2016|publisher=Vox Media|access-date=September 15, 2016|archive-date=November 8, 2020|archive-url=https://web.archive.org/web/20201108095451/https://www.theverge.com/2016/9/13/12895358/microsoft-outlook-sunrise-app-merger|url-status=live}}</ref>

Similar to its desktop counterpart, Outlook mobile offers an aggregation of attachments and files stored on [[cloud storage]] platforms; a "focused inbox" highlights messages from frequent contacts, and calendar events, files, and locations can be embedded in messages without switching apps. The app supports a number of email platforms and services, including [[Outlook.com]], [[Microsoft Exchange Server|Microsoft Exchange]] and [[Google Workspace]] (formerly G Suite) among others.

Outlook mobile is designed to consolidate functionality that would normally be found in separate apps on mobile devices, similar to [[personal information manager]]s on [[personal computer]]s. It is designed around four "hubs" for different tasks: "Mail", "Calendar," "Files" and "People". The "People" hub lists frequently and recently used contacts and aggregates recent communications with them, and the "Files" hub aggregates recent attachments from messages, and can also integrate with other online storage services such as [[Dropbox]], [[Google Drive]], and [[OneDrive]].<ref name=verge-acompliandroid>{{cite web|title=Acompli brings its Exchange-friendly email app to Android|url=https://www.theverge.com/2014/9/4/6099341/acompli-brings-its-exchange-friendly-email-app-to-android|website=The Verge|date=September 4, 2014|publisher=Vox Media|access-date=January 31, 2015|archive-date=November 11, 2020|archive-url=https://web.archive.org/web/20201111175719/http://www.theverge.com/2014/9/4/6099341/acompli-brings-its-exchange-friendly-email-app-to-android|url-status=live}}</ref><ref>{{cite web|url=http://recode.net/2014/02/20/acompli-from-zimbra-and-vmware-vets-tees-up-a-swing-at-mobile-email/|title=Acompli, From Zimbra and VMware Vets, Tees Up a Swing at Mobile Email|last=Gannes|first=Liz|date=February 20, 2014|work=[[Re/code]]|access-date=September 29, 2014|archive-date=March 14, 2016|archive-url=https://web.archive.org/web/20160314082445/https://recode.net/2014/02/20/acompli-from-zimbra-and-vmware-vets-tees-up-a-swing-at-mobile-email/|url-status=live}}</ref><ref name="engadget-acompli"/><ref>{{cite web|url=http://mashable.com/2014/04/24/acompli-email-app/|title=Acompli Launches App to Simplify Mobile Email|last=Bell|first=Karissa|work=[[Mashable]]|date=April 24, 2014|access-date=January 30, 2015|archive-date=November 12, 2020|archive-url=https://web.archive.org/web/20201112030417/https://mashable.com/2014/04/24/acompli-email-app/?europe=true|url-status=live}}</ref><ref name="wsj-acompli">{{cite web|url=https://online.wsj.com/news/articles/SB10001424052702304393704579530332026112164?KEYWORDS=Joanna+Stern&mg=reno64-wsj|title=You're Emailing Wrong: The Best Mobile Apps for Managing Your Inbox|last=Stern|first=Joanna|date=April 29, 2014|publisher=[[The Wall Street Journal]]|access-date=September 29, 2014|archive-date=October 8, 2020|archive-url=https://web.archive.org/web/20201008222519/https://www.wsj.com/articles/SB10001424052702304393704579530332026112164|url-status=live}}</ref> To facilitate indexing of content for search and other features, emails and other information are stored on external servers.<ref name=witpro-outlooksecurity>{{cite web|last1=Redmond|first1=Tony|title=Do the ex-Acompli now Outlook clients really compromise security or is everyone overreacting?|url=http://windowsitpro.com/blog/do-ex-acompli-now-outlook-clients-really-compromise-security-or-everyone-overreacting|website=Windows IT Pro|publisher=Penton|access-date=January 31, 2015|archive-date=September 1, 2016|archive-url=https://web.archive.org/web/20160901100626/http://windowsitpro.com/blog/do-ex-acompli-now-outlook-clients-really-compromise-security-or-everyone-overreacting|url-status=live}}</ref>

Outlook mobile supports a large number of different e-mail services and platforms, including [[Microsoft Exchange Server|Exchange]], [[iCloud]], [[Gmail]], [[Google Workspace]] (formerly G Suite), [[Outlook.com]], and [[Yahoo! Mail]].<ref>{{cite web|url=http://www.digitalspy.com/tech/news/a567986/best-new-mobile-apps-for-ios-android-ifttt-midrive-more.html#~oRcNVU2vVxDLXK|title=Best new mobile apps for iOS, Android: IFTTT, miDrive, more|last=Langshaw|first=Mark|date=April 30, 2014|publisher=[[Digital Spy]]|access-date=September 29, 2014|archive-date=April 13, 2020|archive-url=https://web.archive.org/web/20200413014420/https://www.digitalspy.com/tech/apps/a567986/best-new-mobile-apps-for-ios-android-ifttt-midrive-more/#~oRcNVU2vVxDLXK|url-status=live}}</ref><ref>{{cite web|url=https://www.theguardian.com/technology/2014/apr/28/best-iphone-ipad-apps-tynker-acompli|title=20 best iPhone and iPad apps this week|last=Dredge|first=Stuart|date=April 28, 2014|work=[[The Guardian]]|access-date=September 29, 2014|archive-date=July 24, 2020|archive-url=https://web.archive.org/web/20200724230302/https://www.theguardian.com/technology/2014/apr/28/best-iphone-ipad-apps-tynker-acompli|url-status=live}}</ref> The app supports multiple email accounts at once.<ref name=zdnet-iosreview>{{cite web|last1=Kendrick|first1=James|title=Acompli for iOS review: Must-have app for BYOD|url=https://www.zdnet.com/article/acompli-for-ios-review-must-have-app-for-byod/|website=ZDNet|publisher=CBS Interactive|access-date=January 31, 2015|archive-date=August 8, 2020|archive-url=https://web.archive.org/web/20200808180954/https://www.zdnet.com/article/acompli-for-ios-review-must-have-app-for-byod/|url-status=live}}</ref>

Emails are divided into two inboxes: the "Focused" inbox displays messages of high importance, and those from frequent contacts. All other messages are displayed within an "Other" section.<ref name=witpro-outlooksecurity/><ref name=cnet-betterapps>{{cite web|title=Better email apps for your iPhone|url=https://www.cnet.com/news/email-apps-for-your-iphone-ipad/|website=CNET|publisher=CBS Interactive|access-date=January 31, 2015|archive-date=October 8, 2020|archive-url=https://web.archive.org/web/20201008222519/https://www.cnet.com/news/email-apps-for-your-iphone-ipad/|url-status=live}}</ref> Files, locations, and calendar events can be embedded into email messages. Swiping gestures can be used for deleting messages.<ref name="engadget-acompli">{{cite web|url=https://www.engadget.com/2014/05/03/irl-acompli/|title=Test-driving Acompli: Could an email app be reason enough to go back to the iPhone?|last=Bowen|first=Andy|date=May 3, 2014|work=[[Engadget]]|access-date=September 28, 2014|archive-date=July 26, 2020|archive-url=https://web.archive.org/web/20200726155407/https://www.engadget.com/2014-05-03-irl-acompli.html|url-status=live}}</ref><ref name=Vogel2014>{{cite web|url=http://www.itproportal.com/2014/09/15/mobile-app-of-the-day-acompli/|title=Mobile app of the day: Acompli|last=Vogel|first=Sandra|work=ITProPortal |date=September 15, 2014|access-date=September 28, 2014|archive-date=July 26, 2020|archive-url=https://web.archive.org/web/20200726154822/https://www.itproportal.com/2014/09/15/mobile-app-of-the-day-acompli/|url-status=live}}</ref><ref>{{cite web|url=http://www.phonearena.com/news/Accompli-arrives-for-Android-intelligent-email-wrapped-in-calendar-and-cloud-storage_id60636|title=Accompli arrives for Android: intelligent email wrapped in calendar and cloud storage|last=P.|first=Daniel|date=September 12, 2014|publisher=PhoneArena|access-date=September 28, 2014|archive-date=September 27, 2020|archive-url=https://web.archive.org/web/20200927001238/https://www.phonearena.com/news/Accompli-arrives-for-Android-intelligent-email-wrapped-in-calendar-and-cloud-storage_id60636|url-status=live}}</ref><ref>{{cite web|url=https://thenextweb.com/apps/2014/04/27/perfect-ios-email-app-finally-exists-much-just-email/|title=Acompli: a Perfect iOS Email App but We Wish it Wasn't Free|last=Williams|first=Owen|date=April 27, 2014|work=The Next Web|access-date=September 29, 2014|archive-date=November 28, 2020|archive-url=https://web.archive.org/web/20201128200518/https://thenextweb.com/apps/2014/04/27/perfect-ios-email-app-finally-exists-much-just-email/|url-status=live}}</ref>

Like the desktop Outlook, Outlook mobile allows users to see appointment details, respond to Exchange meeting invites, and schedule meetings. It also incorporates the three-day view and "Interesting Calendars" features from Sunrise.<ref>{{Cite web|date=September 13, 2016|title=Introducing Outlook's new and improved calendar on iOS and Android|url=https://www.microsoft.com/en-us/microsoft-365/blog/2016/09/13/introducing-outlooks-new-and-improved-calendar-on-ios-and-android/|access-date=March 26, 2021|website=Microsoft 365 Blog|language=en-US|archive-date=April 21, 2021|archive-url=https://web.archive.org/web/20210421073412/https://www.microsoft.com/en-us/microsoft-365/blog/2016/09/13/introducing-outlooks-new-and-improved-calendar-on-ios-and-android/|url-status=live}}</ref>

Files in the Files tab are not stored offline; they require Internet access to view.

==== Security ====
{{Update section|date=October 2022|reason=Data is secured with TLS version 1.2 over HTTPS connections end-to-end, between Microsoft 365 or Office 365 and the app, as per https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/outlook-for-ios-and-android/outlook-for-ios-and-android|inaccurate=yes}}
Outlook mobile temporarily stores and indexes user data (including email, attachments, calendar information, and contacts), along with login credentials,<ref name=oauth-office-365>{{cite web|title=New access and security controls for Outlook for iOS and Android|url=https://blogs.office.com/2015/06/10/new-access-and-security-controls-for-outlook-for-ios-and-android|website=Office Blogs|date=June 10, 2015|access-date=June 10, 2015|archive-date=July 20, 2020|archive-url=https://web.archive.org/web/20200720105033/https://www.microsoft.com/de-de/microsoft-365/blog/2015/06/10/new-access-and-security-controls-for-outlook-for-ios-and-android/|url-status=dead}}</ref> in a "secure" form on [[Microsoft Azure]] servers located in the United States.<ref name=outlook_ios>{{cite web|title=Outlook for iOS and Android|url=https://technet.microsoft.com/EN-US/library/mt465744(v=exchg.150)|website=Microsoft TechNet|access-date=January 11, 2016|archive-date=April 13, 2020|archive-url=https://web.archive.org/web/20200413014426/https://docs.microsoft.com/en-us/exchange/clients/outlook-for-ios-and-android/use-basic-auth?view=exchserver-2019|url-status=live}}</ref> On Exchange accounts, these servers identify as a single [[Exchange ActiveSync]] user in order to fetch e-mail. Additionally, the app does not support [[mobile device management]], nor allows administrators to control how third-party [[cloud storage service]]s are used with the app to interact with their users. Concerns surrounding these security issues have prompted some firms, including the [[European Parliament]], to block the app on their Exchange servers.<ref name=networkworld-outlookapp>{{cite web|title=Outlook for iOS, Android flagged for inherent security flaws|url=https://www.networkworld.com/article/935186/outlook-for-ios-android-flagged-for-inherent-security-flaws.html|website=NetworkWorld|date=February 2, 2015|access-date=February 7, 2015|archive-date=April 28, 2024|archive-url=https://web.archive.org/web/20240428135719/https://www.networkworld.com/article/935186/outlook-for-ios-android-flagged-for-inherent-security-flaws.html|url-status=live}}</ref><ref name=techtarget-outlooksecurity>{{cite web|title=Security issues lead IT to block Outlook for iOS|url=http://searchconsumerization.techtarget.com/news/2240239514/Security-issues-lead-IT-to-block-Outlook-for-iOS|website=TechTarget|access-date=February 7, 2015|archive-date=September 21, 2020|archive-url=https://web.archive.org/web/20200921082311/https://searchmobilecomputing.techtarget.com/news/2240239514/Security-issues-lead-IT-to-block-Outlook-for-iOS|url-status=dead}}</ref><ref name=itworld-eublock>{{cite web|title=EU Parliament blocks new Outlook apps over privacy concerns|url=http://www.itworld.com/article/2881635/eu-parliament-blocks-new-outlook-apps-over-privacy-concerns.html|website=IT World|date=February 9, 2015|access-date=February 10, 2015|archive-date=April 24, 2017|archive-url=https://web.archive.org/web/20170424135557/http://www.itworld.com/article/2881635/eu-parliament-blocks-new-outlook-apps-over-privacy-concerns.html|url-status=dead}}</ref> Microsoft maintains a separate, pre-existing [[Outlook Web Access]] app for Android and iOS.<ref name=itworld-eublock/>

==== Outlook Groups ====
Outlook Groups was a mobile application for [[Windows Phone]], [[Windows 10 Mobile]], [[Android (operating system)|Android]] and [[iOS]] that could be used with an Office 365 domain Microsoft Account, e.g. a work or school account. It is designed to take existing email threads and turn them into a group-style conversation. The app lets users create groups, mention their contacts, share Office documents via OneDrive and work on them together, and participate in an email conversation. The app also allows the finding and joining of other Outlook Groups. It was tested internally at Microsoft and launched September 18, 2015, for Windows Phone 8.1 and Windows 10 Mobile users.<ref>{{cite web|url=http://www.windowscentral.com/outlook-groups-app-now-available-windows-10-mobile|title=Outlook Groups app is now available for Windows 10 Mobile and Windows Phone 8.1|work=Windows Central|date=September 19, 2015|access-date=October 2, 2015|archive-date=June 29, 2016|archive-url=https://web.archive.org/web/20160629064836/http://www.windowscentral.com/outlook-groups-app-now-available-windows-10-mobile|url-status=live}}</ref>

After its initial launch on Microsoft's own platforms the application was released for [[Android (operating system)|Android]] and [[iOS]] on September 23, 2015.<ref name=Outlook-Groups-for-Android-launch>{{cite news|last=Edmonds|first=Rich|title=Microsoft releases Outlook Groups for Android to help you engage with your team.|url=http://www.androidcentral.com/microsoft-releases-outlook-groups-android-help-you-engage-your-team|newspaper=Android Central|date=September 23, 2015|access-date=September 23, 2015|archive-url=https://web.archive.org/web/20161117104933/http://www.androidcentral.com/microsoft-releases-outlook-groups-android-help-you-engage-your-team|archive-date=November 17, 2016|url-status=dead}}</ref>

Outlook Groups was updated on September 30, 2015 to introduce a deep linking feature as well as fix a bug that blocked the "send" button from working.{{Citation needed|date=June 2024}} In March 2016 Microsoft added the ability to attach multiple images and the most recently used document to group messages, as well as the option to delete conversations within the application program.<ref>{{cite web|url=http://mspoweruser.com/outlook-groups-ios-updated-new-features/|title=Outlook Groups for iOS updated with new features.|work=MSPowerUser|date=March 29, 2016|first=Michael|last=Allison|access-date=May 5, 2020|archive-date=September 20, 2020|archive-url=https://web.archive.org/web/20200920121510/https://mspoweruser.com/outlook-groups-ios-updated-new-features/|url-status=live}}</ref>

Outlook Groups was retired by Microsoft on May 1, 2018.<ref>{{cite web|title=Outlook Groups app is retiring.|url=https://support.office.com/en-us/article/outlook-groups-app-is-retiring-17ef4874-8b2a-4176-8c7e-998997c68334|access-date=May 5, 2020|archive-date=August 10, 2020|archive-url=https://web.archive.org/web/20200810041258/https://support.microsoft.com/en-us/office/outlook-groups-app-is-retiring-17ef4874-8b2a-4176-8c7e-998997c68334?ui=en-us&rs=en-us&ad=us|url-status=live}}</ref> The functionality was replaced by adding the "Groups node" to the folder list within the Outlook mobile app.<ref>{{cite web |title=Use Groups in the Outlook mobile app |url=https://support.office.com/en-us/article/use-groups-in-the-outlook-mobile-app-7804076e-0acc-48f6-87a1-083b98a5ffa2 |access-date=May 5, 2020 |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112003907/https://support.microsoft.com/en-us/office/use-groups-in-the-outlook-mobile-app-7804076e-0acc-48f6-87a1-083b98a5ffa2?ui=en-us&rs=en-us&ad=us |url-status=live }}</ref>

== Internet standards compliance ==

=== HTML rendering ===
Outlook 2007 was the first Outlook to switch from the [[Internet Explorer]] rendering engine to [[Microsoft Word 2007]]'s. This meant that [[HTML]] and [[Cascading Style Sheets]] (CSS) items not handled by Word were no longer supported. On the other hand, HTML messages composed in Word look as they appeared to the author.<ref>{{cite web |url=http://www.email-standards.org/clients/microsoft-outlook-2007/ |title=Microsoft Outlook 2007 Report &#124; Email Standards Project |work=email-standards.org |access-date=February 24, 2013 |archive-date=November 24, 2010 |archive-url=https://web.archive.org/web/20101124012315/http://www.email-standards.org/clients/microsoft-outlook-2007 |url-status=dead }}</ref> This affects publishing newsletters and reports, because they frequently use intricate HTML and CSS to form their layout. For example, forms can no longer be embedded in an Outlook email.

=== Support of CSS properties and HTML attributes ===
Outlook for Windows has very limited CSS support compared to various other e-mail clients. Neither [[Cascading Style Sheets#CSS 1|CSS1 (1996)]] nor [[Cascading Style Sheets#CSS 2|CSS2 (1998)]] specifications are fully implemented and many CSS properties can only to be used with certain HTML elements for the desired effect.<ref name="campaignmonitor">{{cite web|url=http://www.campaignmonitor.com/css/|title=CSS Support Guide for Email Clients – Campaign Monitor|access-date=September 6, 2012|archive-date=January 15, 2021|archive-url=https://web.archive.org/web/20210115055555/https://www.campaignmonitor.com/css/|url-status=live}}</ref> Some HTML attributes help achieve proper rendering of e-mails in Outlook, but most of these attributes are already deprecated in the [[HTML#HTML version timeline|HTML 4.0 specifications (1997)]].<ref>{{cite web|url=http://www.w3.org/TR/1998/REC-html40-19980424/|title=HTML 4.0 Specification|access-date=September 6, 2012|archive-date=July 27, 2008|archive-url=https://web.archive.org/web/20080727143129/http://www.w3.org/TR/1998/REC-html40-19980424/|url-status=live}}</ref> In order to achieve the best compatibility with Outlook, most HTML e-mails are created using multiple boxed tables, as the table element and its sub-elements support the width and height property in Outlook. No improvements have been made towards a more standards-compliant email client since the release of Outlook 2007.<ref>{{cite web |url=https://www.campaignmonitor.com/blog/post/3769/a-designers-guide-to-outlook-2013|title=A designer's guide to Outlook 2013 and Office 365 |access-date=July 22, 2014|url-status=dead|archive-date=November 28, 2014|archive-url=https://web.archive.org/web/20141128231246/https://www.campaignmonitor.com/blog/post/3769/a-designers-guide-to-outlook-2013}}</ref>

=== Transport Neutral Encapsulation Format ===
{{Main|Transport Neutral Encapsulation Format}}

Outlook and Exchange Server internally handle messages, appointments, and items as objects in a data model which is derived from the old proprietary [[Microsoft Mail]] system, the [[Rich Text Format]] from [[Microsoft Word]] and the complex [[Object linking and embedding|OLE]] general data model.<ref>Outlook Data Model Reference (page on the MailItem object class members), MSDN development documentation, [http://msdn.microsoft.com/en-us/library/ff861252.aspx] {{Webarchive|url=https://web.archive.org/web/20111123213722/http://msdn.microsoft.com/en-us/library/ff861252.aspx|date=November 23, 2011}}, retrieved May 2011</ref> When these programs interface with other protocols such as the various Internet and [[X.400]] protocols, they try to map this internal model onto those protocols in a way that can be reversed if the ultimate recipient is also running Outlook or Exchange.<ref name="tnefphilosophy">[http://msdn.microsoft.com/en-us/library/cc815562%28v=office.14%29.aspx Transport-Neutral Encapsulation Format (TNEF) | Outlook 2010] {{Webarchive|url=https://web.archive.org/web/20170520012521/https://msdn.microsoft.com/en-us/library/cc815562(v=office.14).aspx |date=May 20, 2017 }}. ''Microsoft''. July 28, 2014. Retrieved May 29, 2020.</ref>

This focus on the possibility that emails and other items will ultimately be converted back to Microsoft Mail format is so extreme that if Outlook/Exchange cannot figure out a way to encode the complete data in the standard format, it simply encodes the entire message/item in a proprietary binary format called [[Transport Neutral Encapsulation Format]] (TNEF) and sends this as an attached file (usually named "winmail.dat") to an otherwise incomplete rendering of the mail/item. If the recipient is Outlook/Exchange it can simply discard the incomplete outer message and use the encapsulated data directly, but if the recipient is any other program, the message received will be incomplete because the data in the TNEF attachment will be of little use without the Microsoft software for which it was created.<ref name="tnefphilosophy" /> As a workaround, numerous tools for partially decoding TNEF files exist.

=== Calendar compatibility ===
Outlook does not fully support data and syncing specifications for calendaring and contacts, such as [[iCalendar]], [[CalDAV]], [[SyncML]], and [[vCard]] 3.0. Outlook 2007 claims to be fully iCalendar compliant; however, it does not support all core objects, such as VTODO or VJOURNAL.<ref>{{cite web|url=https://www.microsoft.com/office/editions/prodinfo/compare.mspx#EBAA|title=Microsoft Office 2003 editions comparison|publisher=Microsoft|access-date=October 3, 2008|archive-date=January 7, 2021|archive-url=https://web.archive.org/web/20210107173129/http://www.microsoft.com/office/editions/prodinfo/compare.mspx#EBAA|url-status=live}}</ref> Also, Outlook supports vCard 2.1 and does not support multiple contacts in the vCard format as a single file. Outlook has also been criticized for having proprietary "Outlook extensions" to these Internet standards.

=== .msg format ===

Outlook (both the web version and recent non-web versions) promotes the usage of a proprietary <code>.msg</code> format<ref name=msgspec>{{cite web|url=https://docs.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-oxmsg/b046868c-9fbf-41ae-9ffb-8de2bd4eec82|title=[MS-OXMSG]: Outlook Item (.msg) File Format|date=February 15, 2022 }}</ref> to save individual emails, instead of the standard [[.eml]] format. Messages use {{Mono|.msg}} by default when saved to disk or forwarded as attachments. Compatibility with past or future Outlook versions is not documented nor guaranteed;<ref>{{cite web|url=https://answers.microsoft.com/en-us/outlook_com/forum/oemail-osend/archiving-emails-in-msg-format/974b19f1-dc45-4866-aeb4-ac36e46e4636|author=Dane (MS)|title=Archiving emails in msg format|access-date=May 20, 2021|archive-date=May 20, 2021|archive-url=https://web.archive.org/web/20210520065856/https://answers.microsoft.com/en-us/outlook_com/forum/oemail-osend/archiving-emails-in-msg-format/974b19f1-dc45-4866-aeb4-ac36e46e4636|url-status=live}}</ref> the format saw over 10 versions released since version 1 in 2008.<ref name=msgspec/>

The standard {{Mono|.eml}} format replicates the format of emails as used for transmission and is therefore compatible with any email client which uses the normal protocols. Standard-compliant email clients, like [[Mozilla Thunderbird]], use additional headers to store software-specific information related e.g. to the local storage of the email, while keeping the file plain-text, so that it can be read in any [[text editor]] and searched or indexed like any document by any other software.

== Security concerns ==
As part of its [[Trustworthy Computing]] initiative, Microsoft took corrective steps to fix Outlook's reputation for a lack of security in Office Outlook 2003. Among the most publicized security features are that Office Outlook 2003 does not automatically load images in HTML emails or permit opening executable attachments by default, and includes a built-in Junk Mail filter.<ref>{{cite web |url=http://www.uwec.edu/help/outlook03/MAIL-junk.htm |title=Microsoft Outlook 2003: Using Junk E-mail Filters |work=uwec.edu |publisher=University of Wisconsin-Eau Claire |access-date=September 22, 2014 |archive-date=July 4, 2017 |archive-url=https://web.archive.org/web/20170704090313/http://www.uwec.edu/help/outlook03/MAIL-junk.htm |url-status=dead }}</ref> Service Pack 2 has augmented these features and adds an anti-[[phishing]] filter.<ref>{{cite web|url=https://www.microsoft.com/athome/security/email/outlook_sp2_filters.mspx|title=Microsoft Internet Safety and Security Center|publisher=Microsoft|access-date=April 17, 2020|archive-date=June 4, 2011|archive-url=https://web.archive.org/web/20110604165931/http://www.microsoft.com/athome/security/email/outlook_sp2_filters.mspx|url-status=live}}</ref>

== Outlook add-ins ==
Outlook [[Plug-in (computing)|add-ins]] are small additional programs for the Microsoft Outlook application, mainly purposed to add new functional capabilities into Outlook and automate various routine operations. The term also refers to programs where the main function is to work on Outlook files, such as [[Synchronization (computer science)|synchronization]] or [[Backup|backup utilities]]. Outlook add-ins may be developed in [[Microsoft Visual Studio]]<ref>{{cite web|url= https://www.pcworld.com/article/159204/top_10_reasons_to_use_outlook.html|title= Top 10 Reasons to Use Outlook|date= February 10, 2009|work= PCWorld|access-date= September 17, 2017|archive-date= September 17, 2020|archive-url= https://web.archive.org/web/20200917054053/https://www.pcworld.com/article/159204/ms_outlook_enterprise.html|url-status= dead}}</ref> or third-party tools such as Add-in Express. Outlook add-ins are not supported in [[Outlook Web App]].

From Outlook 97 on, Exchange Client Extensions are supported in Outlook. Outlook 2000 and later support specific [[Component Object Model|COM]] components called Outlook Add-Ins. The exact supported features (such as [[.NET Framework|.NET]] components) for later generations were extended with each release.

=== SalesforceIQ Inbox for Outlook ===
In March 2016, [[Salesforce]] announced that its relationship intelligence platform, [[SalesforceIQ]], would be able to seamlessly integrate with Outlook.<ref>{{Cite web|url=https://techcrunch.com/2016/03/10/salesforce-microsoft-love-grows-with-salesforceiq-outlook-integration/|title=Salesforce-Microsoft love grows with SalesforceIQ-Outlook integration {{!}} TechCrunch|last=Miller|first=Ron|date=March 10, 2016|access-date=September 4, 2017|archive-date=November 29, 2020|archive-url=https://web.archive.org/web/20201129001528/https://techcrunch.com/2016/03/10/salesforce-microsoft-love-grows-with-salesforceiq-outlook-integration/|url-status=live}}</ref> [[SalesforceIQ]] works from inside the Outlook inbox providing data from [[CRM114 (program)|CRM]], email, and customer social profiles. It also provides recommendations within the inbox on various aspects like [[Appointment scheduling software|appointment scheduling]], contacts, responses, etc.

=== Hotmail Connector ===
[[File:Outlook connector.png|thumb|Hotmail Connector setup screen]]
''Microsoft Outlook Hotmail Connector'' (formerly ''Microsoft Office Outlook Connector''), is a discontinued and defunct free add-in for Microsoft Outlook 2003, 2007 and 2010, intended to integrate [[Outlook.com]] (formerly Hotmail) into Microsoft Outlook. It uses DeltaSync, a proprietary Microsoft communications protocol that was formerly used by Hotmail.<ref>{{cite web|url=http://office.microsoft.com/en-us/outlook-help/microsoft-office-outlook-hotmail-connector-overview-HA010222518.aspx|title=Microsoft Office Outlook Hotmail Connector overview|publisher=[[Microsoft]]|archive-url=https://archive.today/20130128151603/http://office.microsoft.com/en-us/outlook-help/microsoft-office-outlook-hotmail-connector-overview-HA010222518.aspx|archive-date=January 28, 2013|work=[[Microsoft Office website]]}}</ref>

In version 12, access to tasks and notes and online synchronization with [[MSN Calendar]] is only available to MSN subscribers of paid premium accounts. Version 12.1, released in December 2008 as an optional upgrade, uses [[Windows Live Calendar]] instead of the former [[MSN Calendar]]. This meant that calendar features became free for all users, except for task synchronization which became unavailable. In April 2008, version 12.1 became a required upgrade to continue using the service as part of a migration from [[MSN Calendar]] to [[Windows Live Calendar]].<ref>{{cite web |url=http://ask.officelive.com/smallbusiness/blogs/team/archive/2009/04/02/outlook-connector-users-you-must-upgrade-to-a-new-version.aspx |title=Transition information for former Office Live Small Business customers – Manage Office 365 – Office 365 – Microsoft Office 365 Community |publisher=Ask.officelive.com |access-date=June 15, 2013 |archive-date=March 23, 2020 |archive-url=https://web.archive.org/web/20200323175849/https://products.office.com/en-us/home?ms.url=office365com&rtc=1 |url-status=dead }}</ref>

Microsoft Outlook 2013 and its newer versions have intrinsic support for accessing Outlook.com and its calendar over the [[Exchange ActiveSync]] (EAS) protocol,<ref name="connector integrated">{{cite web|title=What's new in Outlook 2013|url=https://technet.microsoft.com/en-us/library/cc179110(v=office.15)|work=[[Microsoft TechNet#Library|TechNet Library]]|publisher=Microsoft|access-date=March 1, 2013|date=December 11, 2012|archive-date=September 21, 2020|archive-url=https://web.archive.org/web/20200921041652/https://support.microsoft.com/ja-jp/office/outlook-for-microsoft-365-%E3%81%AE%E6%96%B0%E6%A9%9F%E8%83%BD-51c81e7a-de25-4a34-a7fe-bd79f8e48647?ui=ja-jp&rs=ja-jp&ad=jp|url-status=live}}</ref> while older versions of Microsoft Outlook can read and synchronize Outlook.com emails over the [[Internet Message Access Protocol|IMAP]] protocol.<ref>{{Cite web|url=https://support.office.com/en-us/article/Add-your-Outlook-com-account-in-Outlook-for-Windows-642c1902-bdd9-4dc3-abe7-76d60b148b23|title=Add your Outlook.com account in Outlook for Windows|website=Office Support|publisher=[[Microsoft]]|access-date=June 27, 2017|archive-date=November 11, 2020|archive-url=https://web.archive.org/web/20201111195500/https://support.microsoft.com/en-us/office/add-your-outlook-com-account-in-outlook-for-windows-642c1902-bdd9-4dc3-abe7-76d60b148b23?ui=en-us&rs=en-us&ad=us|url-status=live}}</ref>

=== Social Connector ===
''Outlook Social Connector'' was a free add-in for Microsoft Outlook 2003 and 2007 by Microsoft that allowed integration of social networks such as [[Facebook]], [[LinkedIn]] and [[Windows Live Messenger]] into Microsoft Outlook.<ref>{{cite web|url=http://blogs.office.com/b/office_casual/archive/2010/08/24/how-to-install-the-outlook-social-connector.aspx|access-date=March 1, 2013|last=Thomas|first=Doug|date=August 24, 2010|title=How to install the Outlook Social Connector (video)|work=Office Casual blog|publisher=Microsoft|archive-date=August 3, 2020|archive-url=https://web.archive.org/web/20200803215631/https://www.microsoft.com/en-us/microsoft-365/blog/|url-status=live}}</ref> It was first introduced on November 18, 2009.<ref>{{cite web |title=Announcing the Outlook Social Connector |url=http://blogs.office.com/b/microsoft-outlook/archive/2009/11/18/announcing-the-outlook-social-connector.aspx |work=Outlook Blog |publisher=Microsoft |access-date=March 1, 2013 |date=November 18, 2009 |archive-date=December 25, 2012 |archive-url=https://web.archive.org/web/20121225103458/http://blogs.office.com/b/microsoft-outlook/archive/2009/11/18/announcing-the-outlook-social-connector.aspx |url-status=live }}</ref> Starting with Microsoft Office 2010, Outlook Social Connector is an integral part of Outlook.<ref>{{cite web|title=Changes in Outlook 2010 (for IT pros)|url=https://technet.microsoft.com/en-us/library/cc179110%28office.14%29|work=[[Microsoft TechNet#Library|TechNet Library]]|publisher=Microsoft|access-date=March 1, 2013|date=November 27, 2012|archive-date=August 29, 2014|archive-url=https://web.archive.org/web/20140829213251/http://technet.microsoft.com/en-us/library/cc179110(office.14)|url-status=live}}</ref>

=== CardDAV and CalDAV Connector ===
Since Microsoft Outlook does not support [[CalDAV]] and [[CardDAV]] protocol along the way, various third-party software vendors developed Outlook add-ins to enable users synchronizing with [[CalDAV]] and [[CardDAV]] servers. [[Nextcloud]] recommends the Open Source Caldavsynchronizer.<ref>{{Cite web |last=Poortvliet |first=Jos |date=2016-11-14 |title=Nextcloud offers CalDav Synchronizer for Outlook users |url=https://nextcloud.com/blog/nextcloud-offers-caldav-synchronizer-for-outlook-users/ |access-date=2025-05-19 |website=Nextcloud |language=en}}</ref>  CalConnect<ref>{{cite web |url=http://caldav.calconnect.org/implementations/clients.html |title=CalDAV Clients|url-status=dead|archive-url=http://arquivo.pt/wayback/20160523203324/http://caldav.calconnect.org/implementations/clients.html|archive-date=May 23, 2016}}</ref>  listed software that enables users to synchronize their calendars with CalDAV servers/contacts with CardDAV servers, but most of them are outdated.

== Importing from other email clients ==
Traditionally, Outlook supported importing messages from [[Outlook Express]] and [[IBM Lotus Notes|Lotus Notes]]. In addition, Microsoft Outlook supports [[POP3]] and [[Internet Message Access Protocol|IMAP]] protocols, enabling users to import emails from servers that support these protocols. Microsoft Hotmail Connector add-in (described above) helps importing emails from [[Hotmail]] accounts. Outlook 2013 later integrated the functionality of this add-in and added the ability to import email (as well as a calendar) through [[Exchange ActiveSync]] protocol.<ref name="connector integrated" />

There are multiple methods to get the emails from [[Mozilla Thunderbird|Thunderbird]]. The first is to use a tool<ref>{{cite web |url=http://www.broobles.com/imapsize/index.php |title=IMAPSize |access-date=June 25, 2009 |archive-date=November 22, 2010 |archive-url=https://web.archive.org/web/20101122212435/http://www.broobles.com/imapsize/index.php |url-status=live }}</ref> that can convert a Thunderbird folder to a format that can be imported from Outlook Express. This method must be processed folder by folder. The other method is to use some free tools that keep the original folder structure.<ref>{{cite web|url=http://blog.nektra.com/main/2009/04/14/export-messages-and-folders-from-thunderbird-to-outlook-outlook-express/|title=Export messages and folders from Thunderbird to Outlook/Outlook Express/Windows Mail|date=April 14, 2009|access-date=June 25, 2009|archive-date=May 2, 2009|archive-url=https://web.archive.org/web/20090502142315/http://blog.nektra.com/main/2009/04/14/export-messages-and-folders-from-thunderbird-to-outlook-outlook-express/|url-status=live}}</ref> If Exchange is available, an easier method is to connect the old mail client (Thunderbird) to Exchange using IMAP, and upload the original mail from the client to the Exchange account.<ref>{{Cite web|title=How to Merge PST Files {{!}} PST Merge Tool|url=http://www.howtomergepstfiles.com/|access-date=October 12, 2020|website=www.howtomergepstfiles.com|archive-date=November 8, 2020|archive-url=https://web.archive.org/web/20201108142302/http://www.howtomergepstfiles.com/|url-status=live}}</ref>

== New Outlook for Windows ==
{{Main|Outlook for Windows}}

In May 2022, Microsoft announced a preview release of new Outlook for Windows, available initially to Office Insiders. The new version of Outlook is a [[progressive web app]] based on Outlook.com and offers several new features.<ref>{{cite web |title=The new Outlook for Windows helps you be more productive and in control of your inbox |url=https://insider.microsoft365.com/en-us/blog/the-new-outlook-for-windows-helps-you-be-more-productive-and-in-control-of-your-inbox |language=en-us |access-date=September 14, 2023 |archive-date=August 29, 2023 |archive-url=https://web.archive.org/web/20230829194437/https://insider.microsoft365.com/en-us/blog/the-new-outlook-for-windows-helps-you-be-more-productive-and-in-control-of-your-inbox |url-status=live }}</ref>

The new Outlook for Windows preview later became available to all existing Outlook for Windows users and also users of the free [[Mail (Windows)|Mail and Calendar app]], which was retired in favor of the new app on December 31, 2024.<ref>{{Cite web |title=Outlook for Windows: The Future of Mail, Calendar, and People on Windows 11 - Microsoft Support |url=https://support.microsoft.com/en-gb/office/outlook-for-windows-the-future-of-mail-calendar-and-people-on-windows-11-715fc27c-e0f4-4652-9174-47faa751b199 |access-date=2025-01-08 |website=support.microsoft.com}}</ref><ref>{{cite web |title=Microsoft Outlook for Windows Preview {{!}} Microsoft 365 |url=https://www.microsoft.com/en-us/microsoft-365/outlook/outlook-for-windows |website=www.microsoft.com |access-date=September 14, 2023 |archive-date=September 23, 2023 |archive-url=https://web.archive.org/web/20230923031015/https://www.microsoft.com/en-us/microsoft-365/outlook/outlook-for-windows |url-status=live }}</ref><ref>{{cite web |title=Getting started with the new Outlook for Windows - Microsoft Support |url=https://support.microsoft.com/en-us/office/getting-started-with-the-new-outlook-for-windows-656bb8d9-5a60-49b2-a98b-ba7822bc7627 |website=support.microsoft.com |access-date=September 14, 2023 |archive-date=September 7, 2023 |archive-url=https://web.archive.org/web/20230907194214/https://support.microsoft.com/en-us/office/getting-started-with-the-new-outlook-for-windows-656bb8d9-5a60-49b2-a98b-ba7822bc7627 |url-status=live }}</ref>

The new Outlook has been criticized for having worse performance compared to the previous native versions as well as lack of offline support and missing a unified inbox.<ref>{{Cite web |last= |first= |date=2024-07-05 |title=Even Microsoft's AI says the new Outlook is worse than Mail & Calendar on Windows 11 |url=https://www.windowscentral.com/software-apps/windows-11/even-microsofts-ai-says-the-new-outlook-is-worse-than-mail-and-calendar-on-windows-11 |access-date=2024-08-03 |website=Windows Central |language=en}}</ref> Privacy concerns have also been raised around the decision to synchronise non-Microsoft email accounts with the Microsoft cloud, rather than downloading emails to the local device as previous versions have done.<ref>{{Cite web |last=Alexander |first=Elliot |date=2023-11-27 |title=Microsoft's new Outlook client quietly moves your email to the cloud |url=https://www.xda-developers.com/privacy-implications-new-microsoft-outlook/ |access-date=2025-01-08 |website=XDA |language=en}}</ref>

== Reception ==
{{Section stub|date=June 2025}}
== See also ==
* [[Address book]]
* [[Calendar (Apple)]]—iCal
* [[Comparison of email clients]]
* [[Comparison of feed aggregators]]
* [[Comparison of office suites]]
* [[GNOME Evolution]]
* [[Kontact]]
* [[List of personal information managers]]
* [[Personal Storage Table]] (.pst file)
* [[Windows Contacts]]

== References ==

=== Notes ===
{{Reflist|group=lower-roman}}<references group="lower-alpha" />

=== Citations ===
{{reflist|30em}}

== External links ==
* {{official website}}
* [https://developer.microsoft.com/en-us/outlook Outlook Developer Center]

{{Email clients}}
{{Calendaring software}}
{{Microsoft Office}}
{{Aggregators}}
{{Authority control}}

[[Category:1997 software]]
[[Category:Calendaring software]]
[[Category:Microsoft email software|Outlook]]
[[Category:Microsoft Office|Outlook]]
[[Category:News aggregator software]]
[[Category:Personal information managers]]
[[Category:Windows email clients]]
[[Category:Android (operating system) software]]
[[Category:IOS software]]