Ideally, the name in the server's HELO/EHLO greeting should match the A record for the server which should match the PTR record for that IP address(reverse DNS).  And yes, many domains may be hosted behind one ip address.  I have 150 flowing through our Barracuda filter and about 100 in our Surgemail server.  I allocate two ip addresses really to each, one IPv4 and one IPv6.

Lyle Giese
LCR Computer Services, Inc.

I'm probably wrong about this, but I thought I read a long time ago that email servers using reverse dns are looking for "a" server name, not "the" server name since it is not unusual to have many domain names using the same IP.

 

------ Original Message ------

From: "Lyle Giese" <lyle@lcrcomputer.info>

To: surgemail-list@netwinsite.com

Sent: 9/30/2014 10:20:44 PM

Subject: Re: [SurgeMail List] Reverse lookup problem

 

check it yourself of course.

dig -x 50.205.186.136
or better yet
dig +trace -x 50.205.186.136

dig is part of ISC's bind.  And is included in almost all linux distributions.  Also availble for Windows as a pre-built binary package from ISC.org.

I use one ip address(actually two, one IPv4 and one IPv6 address) for my mail server and it has proper forward and reverse entries.  I recently changed over to a metro ethernet connection from the local cable company and have to deal with them for reverse DNS entries, but I can be persistent.

Lyle Giese
LCR Computer Services, Inc.

On 09/30/14 20:47, Tom Cross wrote:

Hi

We have various Virtual Domains on our Mail server. 

We are finding that some of the outward mail gets bounced or dropped due to failed reverse lookup.

How do others handle this problem?

 

tom cross
Partner Synergist
0418 295 336
tomc@html.net.au