Have you set your username and password in the mail server itself?
If you have this type of error in the server mail log...
Quote:
Mar 3 17:52:41 servername postfix/smtpd[914]: warning: unknown[xx.xx.xxx.xxx]: SASL LOGIN authentication failed: authentication failure
|
You don't.
Also, check that your mail port on the mail server is set to accept connections from the vB server's IP address. It looks like the connection is being refused at the firewall level.
And the one you didn't want to hear, is the mail server info set properly in ACP->Settings->Options->Email Options (at the bottom of the page). HINT: the mail server address for Postfix is almost always mail.domain.name.