On 12.4.2012 14:16, Prabhpal S. Mavi wrote: ... > i know these commands but if you will carefully look into logs, you will > notice that my server is sending mail not receiving. therefor it has > nothing to do with their PTR weather it is correct or in correct. that is > according to the logic. ... If the receiving server is doing callback than the logic is reversed, so no, at that point your server turns into the receiver. please read my *whole* message again, not only the part with the commands. Have a look at the links I provided. -- Kind Regards, Markus Falb Resident do not top post guerilla http://centos.org/modules/tinycontent/index.php?id=16 (The guidelines part) -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 307 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20120412/c9327801/attachment-0005.sig>