They are testing to see whether your mail server is an open relay. There are a number of message formats (mostly malformed) that some mailservers will deliver anyway, even though they shouldn't. What you are seeing is an example of such a mail format. Most Open Relay testers will give a list of all the different types of malformed address types they use. Cheers Ken ----- Original Message ----- From: "Michael Pemberton" <mpember at phreaker.net> To: <thelist at lists.evolt.org> Sent: Monday, September 29, 2003 9:28 AM Subject: Re: [thelist] http://njabl.org/ ?? : John C Bullas <jcbullas at nildram.co.uk> wrote: : : > At 10:55 28/09/2003, you wrote : > >Has anyone else been receiving emails from these guys? They claim: : > > : > >----- start quote from original ----- : > >This is an automated test message for the purpose of finding and : > >adding open relays to our dnsbl. If you have any questions, see : > >http://njabl.org/ : > >----- end quote from original ----- : > > : > >Sounds a bit suspect? : > : > if it is legitimate open relay testing they are looking for their own : > messages to be sent out the other side of your mail server : > : > check the destination address : > : > if it does you get blacklisted ;) or they use you for spamming? : > : > FB : > : : The address seems to be formulated in a mangled fashion. : : something at theirdomain@mydomain : : If they were really testing for sending mail, this seems a bit strange. Why : not use the real address instead of appending my domain to the end? : : Has anyone else out there seen this format for email addresses? The only time : I have seen this is at work where we have an old VAX system for internal mail : and need to append @net to the end of en external address.