This server has been running for over 6 months with no issues. About 5 days ago my customers were no longer able to send emails.
Yes, they all have "My outbound server requires authentication", and have had since the beginning.
There have been no updates installed for about 2 months.
Used tutorial at http://www.howtoforge.com/perfect-se...at-ispconfig-3
The Outlook Clients pass the "Send/Receive" test built into the client, but continue to receive Relay access denied.
Ubuntu Server 10.10