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troubleshooting Question

How to block SMTP at the router level.

Avatar of diablo-26
diablo-26 asked on
Software Firewalls
8 Comments1 Solution266 ViewsLast Modified:

This is kind of urgent because our ISP informed me today that if we don't stop SPAM coming out of our network they will suspend our account.  That means 4 schools without internet service by the end of the week.

I have disabled all relaying on our Exchange 2003 server.  I've allowed no SMTP except from our mail server address from within our Sonic Wall 5060.

Is there a way to block all traffic outbound on port 25 except for traffic orginating from our mail server which is 10.1.1.30?  

Also does anyone know of a good sniffer to try and see where these things are being sent from?  We believe it's a virus sending mail directly from a client computer...  that is it not even using our mail server at all.

Anyone had a similar situation or have a good idea for this?

Thanks,

M
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Avatar of jasonpaine
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