[German]A shot note to users of iPhones and iPads: It seems, that after switching to iOS 11, the mail app shipped with the new operating system does not support Outlook.com, Exchange or Office 365 accounts.
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The update to iOS 11 (for the supported Apple devices) is distributed since a few days. iOS 11 closes several security gaps, but there are some collateral damages that occurs after upgrading to iOS 11. It seems, that the build in iOS mail app isn't compatible with Outlook.com or Exchange accounts.
Microsoft's mail services locked out in iOS 11
Microsoft's support article KB4043473 (You can't send or reply from Outlook.com, Office 365, or Exchange 2016 in iOS 11 Mail.app) dated September 19, 2017 says.
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.
In fact, the entire Microsoft e-mail universe is grounded in iOS 11.
A workaround: use Microsoft's apps
Microsoft's proposal is simple: Use the free Outlook for iOS client from iTunes store under iOS 11. Microsoft's Outlook for iOS client supports several e-mail services like Outlook.com, Office 365 and Exchange Server 2016.
Users of the iOS Mail application synchronizing with Exchange Server 2016 running on Windows Server 2016 can ask the system administrator to disable HTTP/2 in Windows Server 2016 as a workaround. For instructions on how to disable HTTP/2, see the workaround section of KB 4032720: How to deploy custom cipher suite ordering in Windows Server 2016.
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Microsoft and Apple are now working on identifying and resolving the problem. This is also stated in this Apple document. I'm asking at this point, who the heck is testing this stuff before it is released to the customers? Although, the following tweets sheds light to the situation.
I know that the O line and receivers all deserve a healthy helping of the blame, but I actually started to get a headache watching that game
— Jacob Siegal (@JacobSiegal) 12. September 2017
1/2 I've sent bug reports to @Apple during #iOS11 testing that mail cant be sent through native email app using exchange-same on #iOS11GM
— Lt. Andy Norris (@LtAndyNorris) 12. September 2017
