Re: Open Relay Testing
On Wed, Jul 02, 2003 at 09:12:38AM -0400, Gene Grimm wrote:
> What is the best method of testing mail servers to determine if they are
> susceptible to being exploited as an open relay? We have several mail
> servers that I want to verify are "secured". Also, I have been having
> problems with sending mail, specifically to AOL users, through my Zoom
> Internet account at home. I'm not entirely sure I believe Zoom when they say
> that their systems are not open relays. Plus I am considering configuring a
> "relay MTA" on my home Debian box to route all of my outgoing mail through
> our own office mail servers. Are there any HOWTO's describing ways of
> creating a secure relay channel between remote MTA's?
AOL tends to silently discard 'suspect' mail. This is normal.
To check for an open proxy, telnet, from the machine to be tested, to
rt.njabl.org port 2500, (ie, 'telnet rt.njabl.org 2500').
They will connect back to that ip and attempt to relay mail. If they
succeed, that machine will be placed on the NJABL (though you can also
remove yourself when the machine is secured).
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