Okay. I understand what you meant now. I see this mostly as a consequence of tagging: since all the messages are in the same store, it makes sense to get messag

Okay. I understand what you meant now. I see this mostly as a consequence of tagging: since all the messages are in the same store, it makes sense to get messages from the same thread no matter the choice of tags you're viewing. I think it's true that Gmail was the first to do that. [By the way, people are still busy porting these features back to native clients for power users. See http://sup.rubyforge.org/ http://sup.rubyforge.org/ and http://notmuchmail.org/. http://notmuchmail.org/.]