Issue: Apple Mail Not Syncing With Exchange

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.

Troubleshooting Method-1:

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.

Troubleshooting Method-2:

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.

Some Tips and Techniques to resolve the syncing issue:

Make sure that you are using Exchange Server 2010 or later, with the most recent service pack installed. This will work for macOS High Sierra or later versions. To acquire the best possible results, you need to ensure that the software you are using is up to date before you go about setting up an Exchange account in Apple Mail. And to fix the issue Apple mail not syncing with exchange.

In case you are making use of Mail with OS X v10.6 or later version, you can utilize EWS (Exchange Web Services) as a connection to your Exchange server. The OS X Snow Leopard and later versions support EWS.

However, if your Exchange server is not using EWS, you will have to consult your Exchange Administrator and see whether an IMAP connection is possible.

In case certificate authentication has been enabled on the mail server, you have to confirm that your mailbox does not contain more than 11,000 email messages. It is highly recommended by Microsoft that a single Exchange mailbox should not have more than 5,000 email messages.
Yet another workaround is to quit Apple Mail and then open it again. Avoid choosing any other mailbox while your Mail receives new messages. To confirm that Mail has completed downloading and indexing the new email messages, you can select Window -> Activity. Now, you can easily monitor the progress of the downloading process.

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.