Manually combine emails into other conversations when a subject line has changed

Hi ChristiD_A,

Thank you for reaching out to the Microsoft community!

Outlook does not provide a direct feature to merge conversations with different subject lines, the above methods offer alternative ways to manage and reference emails effectively. In Outlook, combining emails into a single conversation can be challenging when the subject line changes. By default, Outlook organizes emails by their subject lines, which means that threads with altered subjects do not automatically group together. 

You can use Manual Forwarding. For each email with a changed subject line, open it and click on "Forward." In the forwarding email, you can mention in the body that this email is part of an ongoing discussion. You can copy and paste text from previous emails to add context.  If you have several emails to forward, do this one by one, ensuring to reference the related emails in your notes.

As a part of the community team, we are here to assist you in troubleshooting and providing information on the availability status of features. However, it's important to note that our community team and the Microsoft product development team operate independently. Therefore, for feature suggestions or design-related queries, we always encourage users to directly submit feedback to the Microsoft product team.

If you don't mind, please provide feedback on this feature request by creating a new post in the Feedback Portal at Outlook · Community (microsoft.com), or directly through your new outlook (Help-->Feedback), Microsoft is committed to enhancing the customer experience by continually examining suggestions to include in the design and development of future product upgrades based on your suggestions.

Your understanding and co-operation are highly appreciated.

Thanks for your precious time. Have a nice day.

Sincerely

Md Ashabul Haque | Microsoft Community Moderator