In previous versions of Mail, if you clicked on your own message in a thread or in the Sent folder and hit reply (⌘-R), the new message would be addressed to yourself, not the original person replied to.

Apple fixed this oversight in OS X Mountain Lion. If you select your own message in a thread or in the Sent folder and reply, the new message will be addressed properly to your previous recipients.

Update

Commenters note that Mail began behaving properly with these kinds of replies around OS X Lion 10.7.4.

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