We have recently moved to Exchange Online and did not seem to have any problem with MacMail for the first few months but now several users are reporting that MacMail will stop receiving and sending e-mails until they close the application and restart it.
I tried removing their mail profile and re-adding it but the issue occurred again. I am setting up the profile by letting the mail client detect the server for the e-mail address and it sets it up as Exchange. So with this happening on multiple OSX clients I am not sure where the problem lies.
Does anyone else have this issue or have you experienced it and now the resolution? It is frustrating for sure.