You would have added your Microsoft Exchange account to your Apple Mail. But the Apple mail not syncing with exchange. In other words, the syncing is simply not up to date. You’d have tried removing, re-adding, and then rebuilding your mailboxes. When you rebuild the mailboxes, everything used to get updated correctly. However, syncing may not happen.
Another associated situation could be that you’d able to send emails from your account. The recipients will also receive your emails immediately. However, your Inbox won’t be updated with the new emails. If the syncing had happened correctly, then you should be able to see the new email messages in your Inbox!
You’d have tried rebuilding the mailboxes over and over again. You’d have attempted to restart your Mac device and then open your mails. Here again, if you find that your Sent items are up to date, but the same issue persists with the Inbox, make use of the troubleshooting methods given below.
One possible workaround is that you can delete the Exchange account on your Mac device completely and then create a new one. Some users say that this troubleshooting method works fine for some time. But after a while, they have to repeat the process. This task is also very time-consuming because the email database is quite huge. Furthermore, some of the email attachments get lost and this might happen very often.
Some users say that the problem might be occurring because of a security patch applied to the Exchange server. Other users recommend using a third-party email client (instead of using the Exchange sync process). In case you are using a third-party client, it will be utilizing time-based polling for querying your mail server for all the new messages. The people who have used a third-party email client say that it is not an ideal solution, but it seems to work for them.
The troubleshooting methods and the tips and techniques provided above should help you fix the Apple Mail not syncing with Exchange issue. Once the problem gets resolved, the proper syncing will take place (between your Apple Mail and Exchange) and your Inbox will be updated with all the new messages.