Legacy Outlook for Mac is now deleting threads when emails are replied or forwarded

Hi everyone,

Microsoft has confirmed that this is a known issue affecting Outlook for Mac (Legacy version). Specifically, it impacts the retention of email threads (conversation history) when replying to or forwarding messages. The product team is currently investigating this behavior, and a fix will be released as soon as it becomes available. 

I will continue to closely monitor and will keep this thread updated with any new information or progress. 

Reference: Replying to or forwarding an email does not include the original message in the email body in legac… 

Appreciate your patience and understanding.

Warm thanks.

I have the same problem. i also have same Outlook version in Mac Tahoe 26.5

This issue is in Legacy Outlook view. Not in New view (which i hate as keyboard navigation options are removed)

First check the same mail in Outlook on the web… if it’s still there, the local thread‑map is what’s breaking on reply. then close Outlook and in Finder use “Go to Folder” to open that path and delete the “Microsoft Outlook” folder — it rebuilds and the thread comes back.

Thanks for the answer. It looks like I got an update May 4, which corresponds with the problem appearing. I have outlook 16.110. I am not sure how to access outlook on the web

Hi @Gordon Anderson

Thank you for sharing your concerns. 

I have tested this behavior on my side, and it still shows the previous conversation thread as expected. This issue seems related to a misconfiguration or a client app glitch on your device. 

To troubleshoot this issue, you could try to toggle Conversation view off and on.

Go to View and uncheck Show as Conversations (or Group messages by conversation). 

Wait a moment, then re-enable it. 

This often resolves threading glitches where replies or forwards cause the thread to “disappear” or regroup incorrectly. 

To better address your issue, could you please provide the following information: 

May I know your current Outlook version and build? 

Whether you can access your account via Outlook on the web and try replying to or forwarding an email to see if you encounter the same behavior? 

Any recent changes made since yesterday? 

Please understand that our initial reply may not always immediately resolve the issue. However, with your help and more detailed information, we can work together to find a solution. 

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