I'm experiencing problems on macOS Mojave 10.14.2 with an Exchange Mailbox in Apple Mail. The Exchange Mailbox account only updates once I click Mailbox > Rebuild.

According to the Connection Doctor (Window > Connection Doctor), all connections work properly. Outgoing mail also works. With the same setup on my iPhone 6, iOS 12.1.13, there are no issues and the inbox updates promptly. The issue seems to be related to the Apple Mail on my Desktop computer, and to Exchange accounts only. My Gmail (IMAP) account in Apple Mail works as expected.

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How can I troubleshoot the issue, when one of several mailboxes won’t show new mails?

  • Hi. Asking for votes is more of a meta, let’s focus this clearly on what precise thing you need. I’m guessing you need to troubleshoot if the problem is configuration, corruption locally or if you need the mail admin to look at your account? Can you narrow down what exchange is? Is it O365 or a company hosted exchange server?
    – bmike
    Commented Feb 2, 2019 at 12:47
  • 1
    I asked because I was curious of the magnitude of the problem. If so, I thought it could be related to a more recent release. The only thing I can say is that my OS is setup completely new and that it only happens with the Apple Mail app on Desktop. On mobile, everything works as expected. The Exchange server is from a university, the documentation is unfortunately not more precise. Commented Feb 3, 2019 at 10:31
  • Any solution? I've just had this start happening to me, all of a sudden, on two different (Catalina) machines with the same Exchange account. (It works fine on my iPhone and iPad, too...) Commented Jan 21, 2020 at 21:04

5 Answers 5


It's May, 2022, and I just upgraded to Big Sur, and this problem is still occurring. I did not have this issue before upgrading to Big Sur. So now it's getting worse.


As MS Exchange keeps all of your data on the server there is absolutely no reason why you shouldn't just remove that account. Delete any leftover mailboxes from mail.app and then re-add the Exchange account. I find that often fixes issues between mail.app and Exchange.

As an aside I stopped using mail.app for exchange connectivity (for work) for reasons that there are times when mail.app, Calendar, contacts, reminders, etc. just don't behave as expected when connecting to an Exchange server. Microsoft's (free, last I checked) Outlook client is actually an excellent mail client and I have never had a problem with Outlook on the Mac or on my iPhone.

  • 3
    I tried that a few times, also setting up the server and addresses manually. However, the problem is still there. Ps: Outlook ist not an option for me. I get depressed by using those interfaces. Commented Feb 3, 2019 at 10:28
  • Ugh. I've had nothing but problems using Outlook on Mac—and I've worked in IT since Babbage & Lovelace Ltd. hired me in the good old days. The hash it made of my contacts was the worst.
    – Parapluie
    Commented Apr 11, 2023 at 11:41

I had this problem for a while, but it seems, somehow, to have worked itself out (which is always worrying). To be more explicit:

  • The problem started showing up, very suddenly, about two weeks ago. It affected my two macOS machines, one located at my institution, the other by broadband at home. I could get the messages fine via iOS or Outlook itself (standalone or web).
  • Generally rebuilding immediately showed all new messages.
  • These problems were not fixed by completely removing the accounts and re-entering them (not just disabling and re-enabling them).
  • I did notice that, at least occasionally, even if I didn't rebuild, messages would sometimes show up several hours later.

However, over last weekend (a period when I logged into my machines less often than usual), messages started appearing in a more timely fashion. As of this week, things seem to be back to normal, at least for now.

Very curious, but at least it's working.

Also, FWIW (and for search purposes in the future), a few other bits of evidence for very similar problems over many macOS releases:

OP @Christopher, do you have any updates?

  • The problem seems to have resurfaced... Commented Feb 12, 2020 at 12:54

Same problem here: university-based Exchange account seems to download emails correctly but they don't actually show up in my InBox until I do a "Rebuild." One further symptom: after the Rebuild, the contents of some messages do not display, instead of a message content I see a blank screen. I can then Quit and Restart Mail, and then all previously downloaded messages are displayed normally. (But new messages from the Exchange server do not display until a Rebuild.)


Meanwhile, you can try the shortcut command+shift+N to refresh the account emails.

  • No, the whole point is that neither ‘Get Mail’ nor ‘Synchronize’ works. Commented Jan 22, 2020 at 6:19
  • I couldn’t have dreamt of it.
    – anki
    Commented Jan 22, 2020 at 7:26

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