open relay

[A15]

How do I check to see if my server relays messages??
I have users complaine that they receive NDR's to messages they never sent.....
If my server is a relay how do I fix it??

 

[FaiTHLeSS]

You can test your server here

http://www.ordb.org

but if your server is found to be an open relay they will add it to their blacklist. Until you fix the problem and retest it again.

 

[rye8261]

Try this also

http://www.abuse.net/relay.html

 

[b0banders0n]

you should always check your server to see if it is an open relay. However it is also posible that a spammer is address 'spoofing' their address so any errors get routed away from the spammer.

 

[Marcs41]

Check out the Security part of

http://www.tek-tips.com/faq.cfm?spid=858

Also, those NDR's probably come in as a result of a virus like Doom. Your domain could be used as the sender address, like so many, and of course it will return .. well, to you.
That is very annoying of course, but there is not much you can do about that, how painfull it may be.
Advice your users about it, so they know that is what the result is if people are not protected properly.

By all means, check your own server, but as far as we can tell now, you are the victim and not the cause.

Marc
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[PuzzledUNIX]

The best way to test this:
Open the Exchange Manager and go to Protocols-->SMTP-->Default SMTP Virtual Server--Right Click-->Properties-->Access Tab, Messages Tab and Delivery Tab (Authentication/Delivery/Relay-buttons)will help you to identify the settings on the SMTP engine for you.

I hope it helps.
Regards,

 

[A15]

Thank you all for your help.