>But would even this work? "relay5.ispam.net" is just what is in the HELO >command; it doesn't forward-lookup in the DNS, nor does 207.124.161.54
>backward-lookup in in-addr.arpa [the class C network involved appears to
>be in the idci.net domain, whatever that is].
In which case if this is causing a problem wouldn't it be time to consider
not allowing mail from servers that don't forward/reverse lookup ...