We recently migrated from Exchange 2010 (in SBS 2011) to Exchange 2016. Outlook clients, OWA, ActiveSync (iPhone / iPad) are fine. Autodiscover is in place and all the tests at https://testconnectivity.microsoft.com/
show up with a pass, including the EWS tests.
Accounts in Apple Mail however, do not work. The accounts were set up previously and as the OWA internal and external URLs have not changed (DNS is updated correctly) the accounts should still work, but don't.
Also if we set up the accounts from scratch, autodiscover populates the server settings correctly with the EWS URL, but then the same error:
"Unable to verify account name or password"
We have tried DOMAIN\username, email@example.com, firstname.lastname@example.org, etc. to no avail.
The users do not want to use OWA in Safari. How can we get an Exchange 2016 mailbox working in Apple / Mac Mail?
Thanks in advance as always for any advice.