by rob » Thu May 06, 2010 7:05 am
This does indeed sound like your SMTP has been subject to either a SPAM relay attack or an abusive user. The outgoing mail queue will probably be loaded with a lot of mails and these will either naturally be removed from the queue when their life expires, or simply if you unload the mail server and delete the 'config/outmail' folder in the installation folder. You must now of course track down the source, and the best way to do this is to look at some of the outgong mails (or outgoing mail log) and identify some addresses in their belong to SPAM mails. Then if you search the smtp logs for these entries, you will then be able to trace how those mails got in and then handle any abusive users. You should also check your SMTP relay settings and ensure that SMTP authentication is enabled too.