On 06/23/11 22:32, Tom Cross wrote:
> Hi All
> Is there a way around having outgoing mail from our mail server failing
> to pass reverse lookup done by other servers.
> We are using virtual domains and would like to save the required IP
> addresses.
>
> Is there a work around or are we better off giving each Domain their own IP.
>
> We are a small ISP..
>
>
> Tom Cross
> Partner (Synergist)
> HTMLnet
> 61 2 9288 9488
> 0418 295 336
>HIDDEN@tml.com.au
>
> *
>
> * <http://www.html.net.au/>

I support over 150 domains on our surgemail servers.  I have one public 
IPv4 and two public IPv6 addresses associated with our mirrored set.

IPv4 is behind a NAT.  Since there is no NAT for IPv6, I am giving each 
mirror it's own IPv6 address.

Both servers announce themselves as 'mail3.lcrcomputer.net' in their 
EHLO banners.  The reverse lookups for these ip addresses are all set to 
'mail3.lcrcomputer.net'.

It is normal for email to come from or go to a shared system.  What the 
other guys should be looking for is that the EHLO banner and reverse 
lookup matches on incoming connections.

It is also normal for incoming email not to go to the same machine that 
does outgoing email.  And the outgoing box does not have to accept 
incoming connects on port 25.

Lyle Giese
LCR Computer Services, Inc.