User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3 Build Identifier: version 2.0.0.0 (20070326) When selecting 'view->sort by->read' with threaded on, threads that contain unread messages aren't placed on top (/bottom). This only occurs is the first message in the thread IS read. Reproducible: Always Steps to Reproduce: 1. Mark some messages in old threads as unread 2. Sort by 'read' with threaded on 3. Observe that previously mentioned threads aren't prioritized above threads without unread messages Expected Results: It would be logical if threads with unread are placed on top while sorting on 'read' using IMAP.

xref bug 262319.

http://www.micropipes.com/code/threadbubble/ extension delivers this capability, as noted in bug 262319. works well

This is largely or totally fixed with version 3. Simon, does beta 3 work for you? http://www.mozillamessaging.com/en-US/thunderbird/early_releases/

Closing Incomplete for lack of answers. Feel free to reopen if you can provide more information.

This behavior still happens in Thunderbird 24.3.0. The steps to reproduce are the same as in the description.