Hi,
I am having the same issue today with my account, which is an Office365 account, not IMAP, Using Outlook 16.84.2 on an M1 MacBook Pro running MacOS 12.7.4.
One specific email in my inbox is stuck showing 'Downloading attachments from server' at the top of the preview pane. The email content is showing in the preview pane but the reply and forward buttons are greyed out for this email. I can reply to other emails.
However, after reading this thread I checked and I now realise that all mail sent from this account since yesterday has been stuck in my outbox and not sent, and any new mail I send also gets stuck - even though there is no obvious indication that anything has gone wrong at the time of sending, it just pops up the 'Sending' notification as normal that then disappears.
It is unacceptable for a system I rely on for work for it to silently fail to send mail.
It seems that the account is working with Apple's mail client on my iPhone - I can send mail successfully from there. It's also apparent from there that other things I have done recently like moving emails to different folders have not been synced from my Mac Outlook client either, as they still appear in the Inbox on my phone. Similarly, the 4 emails in the Outbox on my Outlook client are not showing in the Outbox on the phone, so I have no way to force them to send.
Update:
I have resolved this for the time being by:
- Using Apple Mail on my Mac and connecting that to my exchange account
- Manually re-creating the emails stuck in the outbox in Outlook by copying the content across to new mails in Apple Mail (along with apologies to all the recipients for the late replies) and sending from there
- Deleting all the mails in the outbox in Outlook
- Deleting my account from Outlook
- Restarting Outlook
- Adding the account back to Outlook
I can now send emails again from this account in Outlook. The email that had the 'Downloading attachments from server' message previously now appears to be fine.
I am nervous that the problem may recur so I'm just going to have to keep an eye on the outbox and check every sent mail has actually sent. It's strange because it's not like it had completely stopped syncing - it was still receiving incoming mails, it was just sending mail or moving mails from one folder to another that was not syncing, so it was really not obvious that anything was wrong.
Frustrating to have wasted an afternoon on this and I assume the underlying issue is not fixed so there's probably more wasted time to come.