Sendmail trouble with relaying
From: Erik Dörnbach (doernbach_at_elge.de)
Date: Fri, 31 Oct 2003 16:11:24 +0100 To: <firstname.lastname@example.org>
some question, I have a sendmail box running for a number of virtual domains, our main domain is say "aaa.com". I just noticed some funny things starting here, there are some guys using our server against us, by simply opening an smtp connection to us, pretending to be "email@example.com" and sending mail to "firstname.lastname@example.org" - sendmail doesn't see this as a relay or abuse by default.
How can I make sure the only hosts allowed to send in the name of "aaa.com" belong to a certain network/IP range? Guess I missed out a feature or something? Also how can I avoid having mail with empty sender addresses entering the queue?
Thanks for help,
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