I have a single user that cannot send email from the Mac after migrating to Exchange 2013 on-prem. I myself am on the same Exchange server and am using a Mac with Office 2011 and am able to send/receive emails without any issues.
When the user sends an email it goes to the sent mail folder and syncs with the server and can be seen on a windows machine running any other version of Office (same in OWA). I've logged the user in on my Mac and blown away my profile and seeing the same issue. Not sure if this narrows my issue down to the Exchange server receiving the send request from a Mac or if it's some setting in Outlook on the Mac?
I do not see anything in the logs on the server and have not seen any error son the Mac.
Any thoughts as to where my issues is?