= Сообщение: 769 из 7442 ============================================== IPV6 = От : Markus Reschke 2:240/1661 29 May 14 11:47:36 Кому : Scott Little 29 May 14 11:47:36 Тема : SixXs FGHI : area://IPV6?msgid=2:240/1661+536a9273 На : area://IPV6?msgid=3:712/848+5386a2af = Кодировка сообщения определена как: LATIN-1 ================================ ============================================================================== Hello Scott!
May 29 12:51 2014, Scott Little wrote to Markus Reschke:
SL> My mail server will reject RDNS mismatches too - it stops a TONNE of SL> spam. The solution is simply to not try and be cute with SL> "mail.domain.com" if your server isn't actually called "mail". SL> www/ftp/mail can still be CNAMEs as long as the MTA knows what its SL> real name is.
Yep! It takes the name signaled by the sending MTA, performs a reverse lookup of the IP address and compares both names. That's standard! But SixXs seems to look up the MXs, get the IP addresses of the MXs, also get the reverse mapping for those IP addresses and then check if forward and reverse mapping matches. But that fails for MX mail.domain.com being an alias and for MTA farms with load balancers.
BTW: MXs shoudn't be CNAMEs. To set up an alias for a MX record you would do something like this:
