Open Mail Relay

mikel king mikel.king at
Sat Aug 14 18:08:25 UTC 2010

On Aug 14, 2010, at 9:29 AM, peter at wrote:

> I have a machine running FreeBSD, sendmail and majordomo.  I have  
> someone who is on one of those majordomo lists complaining that they  
> are receiving spam from me.  The complainer says I have an open mail  
> relay that I need to fix.
> I went to <> 
>  to test the machine using its IP address. gives a clean  
> bill of health, saying relaying was denied in 17 separate tests.
> I've reviewed my mail logs for the past couple of days and I can't  
> find any entries for any mail addressed to the complainer's domain  
> name except mail that should have been sent.
> Is's test adequate to rule out an open mail relay problem?


	I usually attempt to send from a remote site myself directly before I  
sign off on closing that whole. In addition I always request that the  
complaint include a complete copy of all offending messages so that I  
can properly examine the headers. It is entirely conceivable that the  
complaint about an open relay is valid, but not from your server but  
an impostor. In that case you could try setting a SPF record in your  
DNS to help reduce such impersonations, although that is not a  

	If you have any questions ping me off list.

Mikel King
Senior Editor, BSD News Network
Columnist, BSD Magazine
CEO, Olivent Technologies
~because IT matters~
6 Alpine Court,
Medford, NY 11763
o: 631.627.3055

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