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Beware Office365 users

Microsoft has published the following. Heed carefully if you depend on Office365 email.



Known Issue: Email access in iOS 11



MC119966


Prevent or Fix Issues

Published On : September 19, 2017


If you are using the native mail app on your iPhone or iPad, and upgrade to iOS 11, you may encounter issues.



How does this affect me?



Do to an incompatibility in the new release of iOS, users of the built-in Apple Mail app in iOS 11 may be unable to sync their Office 365 mailbox or login to their accounts. iOS 9 or 10 users are not affected.


What do I need to do to fix this?



Microsoft and Apple are working to resolve this issue and will post more information to the article, below, when it becomes available. In the meantime, we recommend you download the free Outlook for iOS client, available in the App Store. Alternatively, you can avoid updating to iOS 11 until the issue has been fixed.

Posted on Sep 19, 2017 2:11 PM

Reply
5 replies

Sep 19, 2017 6:26 PM in response to Courcoul

Further details:



Symptoms

In the native Mail app (Mail.app) on your iPhone or iPad, you can't send or reply from your Outlook.com, Office 365, or Exchange Server 2016 email account after you upgrade to iOS 11.

Note These issues don’t occur in iOS 10.



Cause

This issue occurs because the Mail app on iOS 11 is not compatible with Outlook.com, Office 365, or Exchange Server 2016 running on Windows Server 2016.



Workaround

To work around this issue, download the free Outlook for iOS client from the App Store. The Outlook for iOS client fully supports various email services, including Outlook.com, Office 365, and Exchange Server 2016.

If you use the Mail app to sync data from Exchange Server 2016 that is running on Windows Server 2016, you can ask the system administrator to disable HTTP/2 in Windows Server 2016 as a workaround.




Sep 20, 2017 11:02 AM in response to Courcoul

Further update from MS:



You can't send or reply from Outlook.com, Office 365, or Exchange 2016 in iOS 11 Mail.app


Symptoms

In the native Mail app (Mail.app) on your iPhone or iPad, you can't send or reply from your Outlook.com, Office 365, or Exchange Server 2016 email account after you upgrade to iOS 11.

Note These issues don’t occur in iOS 10.


Cause

This issue occurs because the Mail app on iOS 11 is not compatible with Outlook.com, Office 365, or Exchange Server 2016 running on Windows Server 2016.



Workaround

To work around this issue, download the free Outlook for iOS client from the App Store. The Outlook for iOS client fully supports various email services, including Outlook.com, Office 365, and Exchange Server 2016.

If you use the Mail app to sync data from Exchange Server 2016 that is running on Windows Server 2016, you can ask the system administrator to disable HTTP/2 in Windows Server 2016 as a workaround. The instructions on disabling HTTP/2 can be found in the Workaround section of KB 4032720: How to deploy custom cipher suite ordering in Windows Server 2016.


Status

Microsoft and Apple are working to resolve this issue and will post more information to the article when it becomes available.

References

For more information, about this issue, see this Apple support website.



Properties

Article ID: 4043473 - Last Review: Sep 19, 2017 - Revision: 19

Exchange Server 2016 Standard Edition, Exchange Server 2016 Enterprise Edition, Microsoft Exchange Online, Microsoft Exchange Online Dedicated, Exchange Online BPOS-F, Exchange Online BPOS-S, Outlook.com


Beware Office365 users

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