Exchange Server 2016 and el capitan 10.11.6 apple mail client
Since migrating users to our new Exchange 2016 on prem server - some users are unable to connect to their exchange mailbox from el capitan 10.11.6 apple mail program. I also tried Thunder bird but it fails on username / password - attempted with admin account. Admin account sets up fine in outlook (windows). IMAP is enabled on the server and the user mailbox.
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