Change a Thread's Subject When the Topic Changes

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On mailing lists, message boards and in group emails, individual messages often spark lively discussions. As these discussions grow longer, the topic can change substantially. Often, it has nothing to do anymore with the subject of the original message.

This is why you should change the subject header line of a message thread when it becomes apparent that the topic of the thread has changed.

Retaining the Original Subject

Depending on where you are, you probably are able to change the subject directly, but this may not be the best path to take. 

Rather than changing the subject, make it clear that you are continuing an old thread and not starting a new one by including the previous subject line with the new one.

If the original subject was "New cloud form discovered" and you want to change it to "The finest English umbrella," the complete new Subject line could be "The finest English umbrella (was: New cloud form discovered)." You can abbreviate the original Subject, of course.

Note: If you reply to a message with a (was:...) block, remove it. It isn't needed any longer.

Caveats When Changing a Subject

  • Don't edit any of the earlier content or thread messages.
  • Don't remove the recipients of the earlier emails.
  • State why you are changing the subject to avoid being considered a threadjacker.

Sometimes Starting Over Is a Better Choice

Note that simply changing the subject line to start a new conversation can lead to display problems for others and for yourself. Email programs and services may lump together the wrong messages in threads.

To avoid this problem and the likelihood of being seen as "threadjacking," which occurs when someone takes over a thread or email discussion and intentionally posts on a subject unrelated to the original post, create a new message with a new subject instead of starting with a reply.