[Nolug] sendmail relay problem on LAN

Hey all,

I've got a little problem. Sendmail started barfing today at a client's site.
Yesterday things worked perfectly, but today, my client is not able to relay
his outgoing mail through my Linux server.

Here is the setup:

domain.com # my domain
domain.dhs.org # sub-domain of dhs.org
reuben.domain.dhs.org # host = server (NAT, bind, sendmail, apache, etc.)
domain # local workgroup & searchlist for windows LAN

Sendmail is set up to relay any mail from 192.168.2.0/24

Here is the error I am getting in /var/log/mail:

Jan 8 18:40:52 reuben sendmail[4679]: g090eCo04679: ruleset=check_mail,
arg1=<mark@domain.com>, relay=mark.domain.dhs.org [192.168.1.3], reject=451
4.1.8 Domain of sender address mark@domain.com does not resolve

Of course, my network is working properly:

PING mark.domain.dhs.org (192.168.1.3) from 192.168.1.1 : 56(84) bytes of
data.
64 bytes from mark.domain.dhs.org (192.168.1.3): icmp_seq=1 ttl=128 time=589
usec

Heh, ping times in microseconds --- haven't seen too many times before ;-)

Ok, two questions:

1). What is the problem, and why is my relay not working anymore?

2). Is my network set up correctly to begin with, with respect to my box
thinking it is $HOSTNAME.domain.dhs.org --- should the hostname be the dhs
subdomain?

Thanks for taking a look at this. All thoughts are appreciated :-)

-- 
Joey Kelly
< Minister of the Gospel | Computer Networking Consultant >
http://joeykelly.dhs.org
"When Government fears the people, it's liberty.
When people fear the Government, it's tyranny."
-- Benjamin Franklin
Ich möchte ein Berliner.
___________________
Nolug mailing list
nolug@nolug.org