I use a number of aliases in my e-mail, mostly for different discussion groups.
I don't remember when this started but...
When I send a message from Mail to a group using an alias, it gets bounces. "From" is populated with the account address (not an alias) and the alias address shows up nowhere in the header.
When I send a message from Google web mail, "From" is populated with the alias.
I have my own domain name, and am set up as imap.
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