I have a fresh install of 3.82.gpl GPL on Centos5. Backed up and restored a few machines from another server (which worked fine, same network, etc).
Everything works , POP3, IMAP, HTTP, etc. but no-one can send outgoing mail from any of the domains. The connections are refused. No ports are blocked, Virtualmin seems to be refusing the connection. Using Outlook Express, Logging in to server using standard auth with same as inbound.
The server receives mail, no prob but won't allow clients to connect for outbound.