Exchange Activesync iOS 11 issues

Not able to connect to Exchange Activesync on iOS 11 using the Blackberry UEM Client app (App Store). All syncing items fail with an “Account error” - i.e. Calendar, contacts, mail, notes, reminders. Please investigate if possible. Thank you.

Replies

I FIXED IT!!!! The issue has to do with Windows Server's implementation of HTTP/2. If you run IIS Crypto, https://www.nartac.com/Products/IISCrypto , choose "Best Practices" and hit apply. Then reboot your server. Viola! You will be able to send and forward with/without html, attachments etc. to your hearts content!!!!!!🙂😎

here you can find a workaround

i set those two req entries, rebooted and everything now works perfectly


https://www.frankysweb.de/ios-11-probleme-mit-exchange-2016-activesync-auf-server-2016/


  • HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters
  • EnableHTTP2Tls = 0
  • EnableHttp2Cleartext = 0

This is not the case, the issue is present even if you set up Exchange on iOS 10 and then upgrade to iOS 11.

I have logged a bug report for this issue and will let you know what I hear back.

Evidently this has to do with the way apple is negotiating http/2 connections, and specifically with how it falls back (or fails to) to http/1.1


For now the workaround I guess is to disable http/2 on your Exchange servers until Apple can fix things from their side. With ios11 hitting the public in a few days we'll be doing this reg hack on our servers tonight.


https://support.microsoft.com/en-us/help/4032720/how-to-deploy-custom-cipher-suite-ordering-in-windows-server-2016

Can’t fix it when you have an Exchange Online account. I seriously doubt Microsoft will disable http/2 on their servers. I’ve had to migrate to FastMail until this is fixed. I may stay there anyway. They coordinated with Apple to support push email.

Great, but I can't read the site and we're also on Windows 2012. Also, since we use o365, we can't do much on the exchange servers since MS handles those. But this is a great building block on what the issue may be.

If I add an Office 365 IMAP account, I can successfully get emails to send via smtp.office365.com The only drawback is you'll have duplicate accounts on your iPhone/iPad. I just have the IMAP account set to fetch manually and all seems to be OK. Also, this will not work on admin accounts as IMAP access is blocked for those. I wish there were an option to choose the sending server without having to add another account. On macOS you can have several outbound servers and if one fails, it goes to the next one.

Very kludgy but works for now.

I am having the same issue in iOS 11 GM. I can receive email on native email app through our exchange server but outgoing mail is Rejected by Server. Funny thing is I can use the Outlook app and it works fine. Has anyone found a solution?

It was not fixed in final GM

UPDATE!!!


Maybe Apple actually read my bug report 🙂


https://support.apple.com/en-us/HT208136

Thank goodness. I sent them 3 bug reports before I received an answer.

I had the same issue, using a Corp O365 account, but after adding my personal Outlook.com account, the Corp account started working fully. Very Odd.

For me, it's working now.


I can only assume Apple got MS to push something on their side (I am on Office 365).

Not for me. Same error. Oh well, back to Outlook. At least now I know they are working on it. Exchange via Office 365. It could also be that their temp fix may need time to replicate through all their servers. I am still unable to setup exchange manually and have to use the modern authentication crap.