Re: sendmail as a secondary MX

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Janet Sullivan wrote:
:> Could it be that sendmail is seeing the domain names in rDNS for the 
:> servers IPs, and deciding that they are local, even if they are set in 
:> the relay-domains file?
:	
:That's IT!!!  Hot damn, I found it.
:
:Let's take poohmail.org as an example.  It has its MX records set like so:
:
:                 IN      MX 10   nj.bgp4.net.
:                 IN      MX 20   tx.bgp4.net.
:
:poohmail.org is listed in /etc/mail/relay-domains.
:
:The tx.bgp4.net box has 8 IP addresses assigned to it.  Even though 
:poohmail.org is not the host name of the box, it is the rDNS for one of 
:the IPs.

    I'm not sure whether this applies to you, but you can lock sendmail to
    a particular IP address with an option.  It could well be that what
    is happening here is that FreeBSD is choosing a different originating IP
    (on the machine with 8 IP addresses) when connecting to the target,
    and that is the IP being rDNS'd.  I forget what the precise option
    is but I know it can be done.

						-Matt