RE: proxy firewall and email

[Jason Diesel <jdiesel () axent com>]

The Raptor Firewall is not a mail stor and forward, therefore it has no
knowledge of the users and so on. It merely proxies the mail traffic that
passes through it, and verifies it for adherance to standards, to make sure
that no hacks and attacks are passing.

The Raptor firewall depends on the internal mail server being correctly
configured to allow mail only for designated reciepients. There is support
within the Raptor Firewall for blackhole lists, check sender domains, telnet
debugging, and some other smaller tricks.

You can also configure the Raptor firewall to only accept mail for certain
domains, so killing the relay effect.

Jason

-----Original Message-----
...
I have a question about Raptor firewall and MS Exchange smtp server behind 
it.  The information below is to the best of my knowledge, but be aware I 
know nothing about either Raptor or Exchange or NT.   Together they seem to 
create an open relay for spam.

The Raptor firewall accepts all mail and passes it to the smtp server for 
delivery.  If the recipient is not a valid user, the mail gets bounced by 
the smtp server, but to the address in the From field, not to the sender or 
last smtp server.  Since you can put anything you want to in that field, 
you can send spam via this relay, albeit perhaps slowly.  The firewall does 
not keep a list of legitimate users, so it  can't reject mail as it should.
...