Who is responsible for broken Autodiscover?

[epmadsen]

Hi -

I have several clients on Rackspace Hosted Exchange. Recently, after updating to iOS 11, Autodiscover is no longer working for these people. They must manually enter all their server information - which sort of defeats the purpose of why I have them stationed there.

I spoke to a support tech at Appriver: they are experiencing the same behavior.

Rackspace is pointing the finger at Apple; they seem to think that the Apple Discussion Boards are some kind of official word from Apple, which they are not. It's merely people like me speculating and trying to figure this out.

There are three current threads on the net, all about a month old which describe the issue:

https://discussions.apple.com/thread/8109311?start=0&tstart=0

https://social.technet.microsoft.co...-no-longer-working-in-ios-11?forum=Exch2016CM

https://github.com/lionheart/openradar-mirror/issues/18416

But none of them point to the real culprit.

I have several clients hosted with Microsoft directly (O365) and there is no issue there. Autodiscover works fine.

I spoke to a friend who told me one of their huge enterprise clients runs on Exchange, and that there are at least 15K iOS 11 devices connecting to their Exchange server without these Autodiscover issues.

I also tested Outlook client on iOS 11 this morning and I get the same behavior. No one seems to be getting this behavior, however on any OS X clients OR iOS 10 devices.

I also spoke to another colleague of mine who said the message that pops up in iOS 11 is very specific regarding Microsoft vs. "other". And that this is NOT specific to iOS 11, as Outlook for Android is acting in a similar fashion.

Appriver and Rackspace both have similar setups: They have forever been offering Hosted Exchange for their customers, but are now also offering Microsoft 365 servers, except their own "brand" and the support goes through Appriver/Rackspace. I'm wondering if there's an issue where Autodiscover is having an issue discerning what's what in their environment.

In any case, it's impossible to tell who is responsible for the issue. My solution may just be to yank clients off Rackspace and place them with Microsoft directly.

But I sure would like to get to the bottom of this. Right now no one seems to want to claim any responsibility.

Thanks
Erik

 

[fmisle]

Hey there!

After further investigation:

Before iOS 11, Autodiscover would first come across port 80 which would allow the Hosted Exchange provider to redirect the request to a secure VIP on the F5.

All requests from the mail app are now on port 443 and now dropping all other connections, which is causing this problem.

The Hosted Exchange provider can not include 443 as all their hundreds of thousands of users would get continual certificate prompts due to the CNAME redirect that is done. We can also not target these with an irule as port 443 is encrypted and we can not unencrypt the traffic.

It looks to be the only solution for these Hosted Mail Providers is for Apple to allow the Autodiscover Request over http and port 80 again.