Newbie here! But with plenty of E-Mail background.

I think that this is a very valid point.  The SMTP Proxy should not let you receive 
mail 1) if it is a MEGA message you will clog up your bandwidth (No thanks!) and 2) 
you run the risk of getting listed your server in the Real-Time Blackhole list if you 
act as an open relay and 3) When the guvnor gets to hear that you are an open relay, 
he starts to question security everywhere else.

Having said that...  Any decent mail server (We use MDaemon Pro V3) ought to have 
Spam, IP Verification and Relay Protection built in!

Kevin
----------
From:   Michael W. Burden[SMTP:[EMAIL PROTECTED]]
Sent:   14 August 2000 13:33
To:     [EMAIL PROTECTED]
Subject:        Testing your SMTP Proxy to make sure that it rejects spam relays

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Here's a quick "how to" for anyone who has configured
the GNAT Box email proxy to only accept mail addressed
to your domain(s)  [Authorization -> Email Proxy ->
Domain(s) to Accept],  and want to verify that the
SMTP proxy is, in fact, rejecting spam relaying.


Telnet into your SMTP server and entering the following
exchange.  You may need to turn on local echo in your telnet
session to see what you are typing.

The responses that you will get from the GNAT Box SMTP Proxy
are shown in parenthesis.  The  "501 Invalid domain"   is the
important one.  If you get  "250 OK"  at this point, then
your GNAT Box is not correctly configured to block an attempt
to relay spam.

Replace  mail.yourdomain.com  with the correct name or IP address
of your mail server.  The other domains and addresses may be
used as shown below.

The gist of what we are doing is logging into an SMTP session
and attempting to send email to  [EMAIL PROTECTED],  which
(hopefully) isn't in the domain that the GNAT Box has been
configured to accept email for.


telnet mail.yourdomain.com 25
(220 SMTP ready)
HELO somedomain.com
(250 OK)
MAIL FROM: [EMAIL PROTECTED]
(250 OK)
RCPT TO: [EMAIL PROTECTED]
(501 Invalid domain)
quit


Mike Burden
Lynk Systems
(616)532-4985
[EMAIL PROTECTED]

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