I am unable to add Outlook account for an on-premises mailbox for in a Hybrid Office 365 solution.
Mail flow works just fine. The autodiscover records are pointing towards Office365 and all of the domain checks are green. It is only when I try to add an Outlook account the search hangs with "An encrypted connection to your mail services is not available"
This is true when adding the mailbox both from inside and outside our network organisation.
I'be been searching this on google, and everywhere I can find only problems relating to adding a migrated mailbox to Office 365, and this problem that I have is just the opposite.
Please advice, I am going desperate.
Edit: I also tried to use the MS Remote Connectivity Analyzer. The last error that I have is:
We were unable to get account settings after a domain redirection.