Exchange 2016 to make friends with Outlook Anywhere?

Question

Outlook

Hello! The situation is as follows, Exchange 2010 was used in counter and there were big troubles with access to it outside the domain. Migrated to 2016, demolished the old one. Now everything works: owa, ecp, autodiscover. On any non-domain computer without a VPN, I enter an email, everything arrives, the boxes are loaded quickly, it has been checked both on Windows and on a poppy (the Microsoft office for poppy has not connected before). The test from the computer (ctrl on Outlook in the tray) does not find any errors, in EMS the test is also OK. Online https://testconnectivity.microsoft.com/tests/exchange test fails. This error is:

Attempting to send an Autodiscover POST request to potential Autodiscover URLs.
Autodiscover settings weren't obtained when the Autodiscover POST request was sent.
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Test Steps
The Microsoft Connectivity Analyzer is attempting to retrieve an XML Autodiscover response from URL for user.
The Microsoft Connectivity Analyzer failed to obtain an Autodiscover XML response.
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Additional Details
Exception details:
Message: The operation has timed out
Type: System.Net.WebException
Stack trace:
at System.Net.HttpWebRequest.GetResponse()
at Microsoft.M365.RCA.Services.RcaHttpRequest.GetResponse()

On mobile phones, Outlook is set, the settings recognize that it is Exchange. It asks for a domain \ login and password, if you enter it incorrectly, it swears. With the correct input, it imitates downloading letters, then writes “everything for today!” and you can see that there was no synchronization, personal folders were not loaded. If you try to send a letter, it goes to sent without errors, but in fact it does not get to the server. Empirically, I created several new boxes and literally threw 3 text letters into them, these boxes cling to the mobile phone and everything works, notifications come in properly. The problem is for both android and ios for all the old minced meat boxes. Some built-in EMAIL clients work, but not all.

Now I have turned on IMAP, like a crutch, everything works on mobile phones through it. But I'm expected to have ActiveSync work. I looked at the mobile policy, but everything seems to be by default, there is only permission to access, in fact, that's all.

Can anyone come across? Or do you have any thoughts? 3 days I fight - there is no sense. I would be very grateful for help. Thank you all in advance!

Answer 1

1. Does ActiveSync for mobile clients work at all? What are the settings? What does Get-ActiveSyncVirtualDirectory say?
2. Are self-signed certificates not used on services?
3. Policies and rules for mobile devices - no extra restrictions?
4. Migration took place. According to the description - the problem is with existing boxes, everything works with new ones. Compare, for fun, permissions and inheritance settings for new and old users in ADUC on the Security tab