On Fri, Feb 03, 2012 at 11:17:29PM +0100, Reindl Harald wrote: > Am 03.02.2012 22:58, schrieb Stephen Harris: > > If your mail server talks to machine with IP address 1.2.3.4 then should > > it say HELO with the 10 address name or the 91 address name? > > if you are not too stupid your internl view and external view of > dns-names is identical and there is no difference *boggle* What? Wow. No. Just no. That won't even work on a toy home network where your ISP sets the rDNS, it definitely won't work on a large corporate network. It only works in a trivial environment. If you're telling me that my internal mail servers must talk to each other via the name pool-173-71-187-61.pitbpa.fios.verizon.net then... well, never mind. -- rgds Stephen