Improper reverse lookup for Mail.

[Pete Ehlke]

On Tue, Sep 03, 2002 at 01:53:16PM -0400, Brett Simpson wrote:
> 
> I currently have a mail server that uses 207.156.7.30
> (mail.hillsboroughcounty.org) to receive email. When the mail server
> sends out an email it uses 207.156.7.11 since it's the first bound
> address on the server. This causes a problem with other receiving mail
> servers using reverse lookups to help reduce spam. Since
> mail.hillsboroughcounty.org is reversed to 207.156.7.30 and not
> 207.156.7.11 this causes a problem. What is the best way to handle this?
> I can't eliminate 207.156.7.11 and I'd rather not force sendmail to only
> use 207.156.7.30 since I'm looking to move this server behind a load
> balance and failover system. Another mail admin suggested I use a CNAME
> but I'm not sure how to do it or even if it will work.
> 
The easiest solution is to add a PTR record for
11.7..156.207.in-addr.arpa pointing to something other than
mail.hillsboroughcounty.org, and tell sendmail to announce itself as
that name when making outbound connections. How to do the latter is
off-topic for this group.

-Pete