DragonFly users List (threaded) for 2005-02
Re: sendmail as a secondary MX
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
As long as sendmail sees that one of the IPs reverses to poohmail.org in
DNS, it refuses to treat it as a relay domain, but insists its local.
I put in a bogus hosts entry to stop sendmail from seeing the rDNS for
poohmail.org. Once I restart sendmail it now acts as a secondary for
the poohmail.org domain just like I expected it to.
Either this behavior is unique to DF sendmail, *or* the sequence and
timing of the start up is different enough from FreeBSD to make a
difference. Perhaps in FreeBSD, sendmail started up early enough that
it couldn't resolve the rDNS entry for all the IPs on the box?!
At any rate, that's the issue. I don't know why FreeBSD let it work,
and not DF, but hey...