Bug in Mountain Lion Mail Sends Replies Using Incorrect Accounts
I’m on a few e-mail mailing lists, and I’ve noticed that Mail, in OS X 10.8, has been doing something odd. Generally, if you have multiple e-mail accounts, when you reply to a message, your reply uses the same account the message was sent to. But I’ve been finding that Mail does not correctly choose the account, and have seen a number of messages bouncing because the selected account is not a member of the mailing lists.
There is a setting in Mail’s Composing preferences where you choose which account to use for new messages, but this shouldn’t affect replies.

I have seen, however, that this is the case, both with mailing lists, and with other e-mails I’ve received. Mail seems to want to apply that account to replies as well as new messages, which is clearly wrong.
So, it looks like you may need to check twice for every single e-mail you send, if you have multiple accounts, and if it’s important to send or not send certain messages with certain accounts. You can do this by looking at the From popup menu when you’re sending or replying to an e-mail. But this is a very serious annoyance, and I hope this gets fixed.
It seems that I’m not alone; there are a few threads on Apple’s support forums (including this one) where other people are reporting the same issue.
Posted: 8/2/2012 by kirk | Filed under: Apple & Mac OS X | Tags: Mac OS X, troubleshooting | 8 Comments »



The problem in this posting seems to be a bit different than what is described in the Apple support thread that you referenced.
What I have observed is that if a message is in an Inbox, the reply is from the same account as the Inbox.
If I have filed the message in a On My Mac folder and reply to that message, the “From” depends upon the preference setting for “Send New Messages From.” If “Send New Messages From” is an account name, the reply uses that account as the From. If “Send New Messages From” is Account of Selected Mailbox, the from is the account at the top of list. Of course, neither is the desired account. In all cases, the from should be the account of the incoming email.
I’ve been seeing this both in folders on my Mac, and in smart mailboxes (I never actually go to my inboxes; I have smart mailboxes for them).
But no matter what, replies should always go from the account the messages were sent to.
thanks for posting this. i thought it was something i was doing wrong.
I have seen this intermittently for a long time on Snow Leopard as well. When I notice it’s happening it’s always the same, I’ll respond to an email and it will use another email address as the from and I will have to restart Mail to get it to stop.
I never saw this happen before Mountain Lion.
Hey! I saw your post as I had the same problem but then I realized I had messed up my settings on Mail.
This may help your problem. I hope so: Basically I had to go through my SMTP outgoing servers and to make sure that all of my accounts were sending via the correct SMTP setting. (I had multiple Gmail accounts so they were all labeled “Gmail.”) I dug around in advanced settings/dialogues to make sure the inbox and smtp addresses matched.
That’s it! :) Maybe it’ll help, maybe it won’t but I figured it couldn’t hurt.
Jason’s solution works quite well for me. It is just that it is hard to find the advanced settings to connect accounts with the right servers. Under account information, click on the drop down of outgoing mail server, then you will find “Edit SMTP server list”. Click on that, then you can see the advanced settings.
Further to Jason’s and Fang’s comments:
SMTP is unrelated to the problem that Kirk and I related. SMTP determines which mail server sends your message, not which email Apple Mail applies to a reply. Using a different SMTP server will not change the “From” email account in a message.