Are you talking about SMTP level filtering? As rejections based on reverse DNS lookups of SMTP HELO greetings are likely to violate RFC 2821 there is no built-in function for this in MercuryS. It would be possible to write an event daemon to do PTR lookups though, but I'm not aware that any such daemon exists.

/Rolf 

Hi,

Could you help me, in which module and how to set up this kind of message filtration (Mercury v4.72)?

Thanks.

d