Do I have an open relay?
fgleiser at cactus.fi.uba.ar
Thu Jun 19 05:51:33 PDT 2003
On Thu, 19 Jun 2003, Andreas Widerøe Andersen wrote:
> I'm a bit nervous here. Recently I've started getting 20-25 mails to my
> Postmaster account on my FreeBSD 4.8RC server running Sendmail
> 8.12.8/8.12.8 each day with a message to Postmaster that the mail could not
> be delivered.
Sendmail by default does not relay, unless you enable PROMICUOUS_RELAY.
To test if you have an open relay, go to: http://www.abuse.net/relay.html
and run a test against your server.
It may be a "rumplestinkin attack", the spammers are trying to guess
account names in your server, postmaster gets a copy of the bounce. Look
at the logs for the full info.
More information about the freebsd-questions