iOS 11 and Exchange 2016:/Exchange Online: Not Kissing Cousins

[Tony Redmond]

Apple released iOS 11 and found that the mail app cannot connect to Exchange Online or Exchange 2016. It’s all to do with HTTP2 connections. Apple tries to connect via ActiveSync but doesn’t do so the way that Exchange likes, or something like that. In any case, maybe now’s the time to consider Outlook for iOS.
https://www.petri.com/ios-11-exchange-not-kissing-cousins

[#2]

How on Earth did that slip past release testing given the number of iOS users who connect to Exchange mail?

[#3]

works fine for me on an iPhone SE with iOS 11, not sure why it would be different on an iPhone SE.

[#4]

Lucky of you...there is a message in the Message Center warning about this...

[#5]

Hi, I have updated iOS 11 on my iPhone 6 and works fine.

[#6]

Exchange Online and Outlook.com run inside a massive environment spread over > 100,000 mailbox servers in multiple datacenter regions. It is possible that your client connected to a server that was willing to negociate an ActiveSync connection. In otherwords, you could be lucky. But the situation is that both MIcrosoft and Apple have acknowledged that a problem exists and needs to be fixed. If you upgrade to iOS 11, you take a chance that mail will continue working (unless you use Outlook for iOS). 

TR

[#7]

The issue was highlighted about 4 days ago. I guess it was known too late in the release cycle.

BTW, the Apple note on the topic is at https://support.apple.com/en-us/HT208136