I just upgraded my 2012 27" iMac to Mountain Lion. I use mail and can receive incoming mail from both my business account and my .me account, but cannot send any mail. I have not changed any mail settings since the upgrade.
The error message:
The SMTP connection to server “smtp.xxxxxxxxxx.com” failed.
Select a different outgoing mail server from the list below or click Try Later to leave the message in your Outbox until it can be sent.
Sending from: smtp.xxxxxxxxxxx.com
I have gone directly to my server site and was able to send a message from there
Any ideas - all settings and passwords seem correct on my end
I had the same issue yesterday and changed it to 587 and worked. Today it isn't working again. Called my ISP and they don't have a clue