"Message failed to send" Red Error box in Outlook 365 for Mac

Anonymous
2023-08-14T06:11:51+00:00

Hi everyone - has anyone had issues with sending emails using Outlook 365 for Macs? Especially a red error box that appears at the bottom (attached) and says "Message failed to send Open" The email is then stuck in drafts with the option to continue editing but it is simply frozen in drafts and the only way is to delete and try again. Alternatively, you can go to the webmail version of outlook, find the drafts folder and send from there. This has been happening on/off for several weeks now, no pattern, just happens occasionally.

This version of Outlook 365 is absolutely **** with so many issues

Outlook | MacOS | Legacy Outlook for Mac | For home

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  1. Anonymous
    2023-09-20T06:12:17+00:00

    I've narrowed it down to replying to emails with Images embedded in the body of the email. Thats where we're having issues. Emails with no images go through fine.

    Spoke to microsoft today and showed him exactly what was happening and he did at least acknowledge there is an issue. This new version absolutely sucks and has wasted so much of our time!

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  2. Anonymous
    2023-09-20T05:54:01+00:00

    Yes exactly!!

    Do you happen to have send later enabled by default in the Settings / Composing ? I believe it might have something to do with the issue. This is not being respected and Outlook trying to send immediately then it's stuck. I reverted this back to zero seconds but didn't fix.

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  3. Anonymous
    2023-09-20T03:57:31+00:00

    Hi - apologies for the delay. I ended up reverting back to the older version of Outlook, we are now back on the new version and it appears that this issue has still not been resolved! I have attached screenshots and hope you get them.

    As others have mentioned, there is no way around this apart from having to shut down Outlook ir go to the OWA and send from the drafts folder there

    PLEASE FIX THIS ISSUE!!!

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  4. Anonymous
    2023-09-18T07:56:27+00:00

    Same issue. It started happening while I was trying to solve the previous issue of attachments and images being stipped from messages. The KB articles recommended switching to the legacy version. After testing legacy I couldn't bare using it so switched back to new version. Now 50% of my message get permanently stuck like this.

    REALLY FRUSTRATING!!

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  5. Anonymous
    2023-09-15T11:54:33+00:00

    Having the same issue on multiple Macs, all running latest OS (13.5.2) and after updating to the September patch release of Outlook for Mac using the New Outlook client (16.77 23091003), except that the consistent behaviour for us is the red error box "Message failed to send" appears and the email is stuck in Outbox (and not in drafts).

    When the email is stuck in Outbox we see similar behaviour; cannot resume editing, cannot send but also cannot delete. The error message when you try is that the email is open in another instance (which is not the case).

    However, if we then open OWA, the stuck email is in the Drafts folder and you can immediately click Send and it works.

    I can also confirm that revert to legacy Outlook does not encounter the same problem.

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