Yehuda Katz is a member of the Ruby on Rails core team, and lead developer of the Merb project. He is a member of the jQuery Core Team, and a core contributor to DataMapper. He contributes to many open source projects, like Rubinius and Johnson, and works on some he created himself, like Thor.
Better Threading in Mail.app
November 19th, 2007
I really like the new Mail.app in Leopard. With Gmail moving to IMAP, I was finally able to get virtually all of the functionality that I’m used to in Gmail on my desktop Mail application, which is really cool.
Well… except for one little thing. Mail.app has threads, but it does not thread Sent Mail in with Received mail. In Gmail, on the other hand, inbound email gets threaded with outbound email, so I get a nice breakdown of the actual discussions I’ve been having. Devoid of outbound context, the threads are frequently confusing or meaningless.
The workaround I came up with is to create a new Smart Folder that includes Inbound email and Outbound email (Inbox and Sent Items). The Smart Mailbox, in threaded mode, correctly handles putting all of the email together. The little caveat is that outbound email that was not a reply to something appears in this view too (it does not appear in Gmail), but I think I actually prefer that mode of operating.

Thomas Aylott, Posted May 13, 2008, 8:34 pm
You can also just select both the inbox and sent mail folders at the same time, therefore combining all their contents on the right.
Byron, Posted June 25, 2008, 2:10 am
I think threading is hopelessly broken in mail.app. First, threading is performed by subject, So unrelated messages get threaded together like “Lunch”, “Meeting”, etc.. Also, the threading is displayed in a flat view, so you loose who responded to who in a larger thread, which is an especially nasty problem for maillists where threading is central.