I just figured this one out, and before I forget it.
I’ve been a user of Thunderbird’s Multiple Identities feature for a while. It allows you to send mail from a single account using multiple identities. So, for example, I have my personal email address for the majority of my email, but I have a second address which is really an alias for my wife and I which we give to day care, schools, etc. And when communicating with said entities I want the email to look as if it came from the alias.
I’m not sure when it changed, but recently even though I have set everything up the same way in Thunderbird, when the email was delivered to the receiver, it would show up as my primary address. Not good.
I immediately suspected the recent releases of Thunderbird, 5.0 & 6.0, but a few searches and I found nothing.
The only other change was switching over to Google Apps to host my personal domain email, I had done that a while ago though. But still poked around anyways.
And wouldn’t you know I found two settings, either one or both of them fixed the problem.
These are both in Mail Settings -> Accounts (note Mail Settings is under the Gear icon in the upper right)
- First I added the email alias to my account by clicking on Add another email address you own link.
- Second I set When replying to a message to Reply from the same address the message was sent to.
Not sure which of these fixed the problem, I suspect the second, but either way, now the receiver correctly sees the alias when I choose to send mail as that identity.