I have several email addresses. A couple gmail ones and cloud one. a few weeks ago the system on my Mac ( mt Lion) started forcing almost all my email to be sent from a wrong email address…even though I select the proper one. It is a headache. any hints?

My email is doing the same thing. I send from the proper (default) address, but replies are going to a different one. In the thread, I can see it sent from the default, but the replies are sent back to me to a different account that the other person doesn't even have the address to! It's happening with one account in particular between my default, personal account and my work account. Both are gmail accounts.

It's very frustrating and I worry it's messing up the other person's contact info for me. It's been doing this the last few months, around the time I upgraded to Mavericks, I think.

It's possible that you have a problem with some outgoing servers and it's just moving through the list until it finds a working one. It will do this if you not have specific SMTP servers locked to each account?

Open Mail's preferences. Select an account and make sure it has the correct SMTP server listed. Also check the login and password for it to make sure it's correct. Check the box to use only that server for that account. Repeat this for all accounts making sure the server login and information are correct.

If an outgoing server fails in the future, you will ger a failure window asking to select another server or try again with the one chosen for that account.

You can also open connection doctor from Mail's main menu (under Window) and run the test. You should have incoming and outgoing servers listed for each account. It will tell you which are working and which aren't. You may also have intermittent failures. Run the test several times.

If this doesn't work, post back more info.