Am 17.07.2011 22:30, schrieb Always Learning: > Here a a few examples: http://sys.u226.com/t21/t21p003.php Just to understand you, could you please explain one of your "examples"? The 2nd one in your list: Organisation: British Telecommunications, EU HELO / EHLO: smtpe1.intersmtp.com HELO IP: 62.239.224.89 MX IP: 62.239.224.234 MX DNS A record: smtp61.intersmtp.com Here smtpe1.intersmtp.com resolves properly forward and reverse, if that is what counts for you. Alexander