Outlook 365 for Mac - not sending attachments

Hi there

We have exactly the same problem.

All Mac's on Monterey 12.4 all Outlook versions 16.63. We are using Google Workspace and all client computers randomly drop attachments.

I have disabled (temporarily) Webroot Antivirus - No difference

Attachments are a mixture of Excel files, PDF's and Word docs.

All these points are exactly the same.

• This does not happen every time—sometimes it doesn't happen for a week and sometimes it happens 5-6 times a day. On average I would say it happens at least 2 times a day.
• Usually on the second email attempt to send my attachment, it goes through, but the odd time it will fail 2-3 times in a row
• It does not happen for any one client in particular and there are no firewall issues on my end
• It will happen for attachments between 30kbs and 15mbs so I gather it is not a size issue, especially when the attachment goes through the second or third time without issue.
• Around 5 weeks ago, support told me an engineering team was going to look into this specifically, but I have not been able to receive any updates on this after asking.

They always work the first time through webmail.

There are over 20 affected users.

Any ideas would be greatly received.

I am also having this issue all of a sudden. No updates appear to be available. It doesn't happen every time, but it's been happening more and more... is there a fix? Safe mode doesn't seem to effect it for me...

I am experiencing the same problem over the last few weeks. Rebooting the computer has not helped.

Shortly after I posted this, my Macbook had to go in for repair for an unrelated issue so was out of action for around a month or so.

During that time I was woking on an old 2014 Macbook Pro running 11.2.1 Big Sur. When I upgraded that to the new Outlook I had the same issues.

On both machines, switching back to the old outlook version seemed to resolve the matter,

There is definitely a major flaw in the new version of Outlook for Mac (when working with a Gmail account at least) which Microsoft have failed to sort...

On both machines it asked for feedback on why I was switching back so have explained exactly why, not that I expect anyone will actually feed back to the technical department responsible for the software development...

Pretty poor from Microsoft to a) let it roll out without picking up and resolving such a fundamental issue, and b) not sorting out a fix in 2+months since I first posted about this. Going to start a new thread and link it to this one since I'm not convinced anyone who monitors these forums will pay much attention to an old thread.

I'm having the exact same problem. Don't know something hasn't sent until I go into the sent file.

I'm having to swap back to Gmail to reliably send emails with attachments, which is laborious.. Plus, I hate the Gmail interface.

I've done updates, nothing seems to be working.

I miss the legacy version. This one just doesn't seem as stable.. and now I can't send emails with attachments, in no pattern I can ascertain. Driving me nuts.

Please fix this Microsoft.

I'm on Version 16.63