Open Relay Checker before Opening MTA

John Griffiths john at
Sun Feb 10 14:46:05 EST 2002

>Also don't assume that all real IP addresses have reverse lookup
>entries associated with them.  
>My ISP (Optusnet) will not enter a reverse DNS entry for my static IP.  
>Does that mean I cannot send mail under this system?
>I suspect there are many others in such a situation.
>Neil Pickford

The answer to that is "YES", sending mail out to a subscription news
service we had all manner of trouble when we moved our mailhost duties to a
server that didn't have a reverse lookup.

we found the problems lay, not so much in the system, but in over-zealous

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