Replacing all instances of my domain and my "other" domain w/ mydomain in fqdn's to hide the real domains but otherwise exact output from files:
cat /etc/hosts
[root@gamma ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
22.33.44.55 gamma.mydomain.com gamma www
MyDomain | Domain Names, Web Hosting, and Free Domain Services
domain mydomain.com
search otherdomain.org
nameserver 192.168.13.1
nameserver 192.168.13.3
(those are my dns servers and work fine to resolve all hosts, as you'll see below:
[root@gamma ~]# dig mx otherdomain.org +short
10 kappa.otherdomain.org.
20 sigma.otherdomain.org.
30 kappa2.otherdomain.org.
[root@gamma ~]# dig mx mydomain.com +short
20 sigma.otherdomain.org.
30 kappa2.otherdomain.org.
40 gamma.mydomain.com.
10 kappa.otherdomain.org.
[root@gamma ~]# dig any otherdomain.org +short
"v=spf1 a mx ~all"
22.22.22.22 (faked IP)
alpha.otherdomain.org. hostmaster.otherdomain.org. 2009120201 10800 3600 1209600 43200
beta.otherdomain.org.
alpha.otherdomain.org.
sigma.otherdomain.org.
30 kappa2.otherdomain.org.
10 kappa.otherdomain.org.
20 sigma.otherdomain.org.
[root@gamma ~]# dig any mydomain.com +short
"v=spf1 a mx -all"
22.22.22.22 (faked IP again)
alpha.mydomain.com. hostmaster.mydomain.com. 2010010801 10800 3600 1209600 43200
alpha.mydomain.org.
delta.mydomain.org.
beta.mydomain.org.
10 kappa.otherdomain.org.
20 sigma.otherdomain.org.
30 kappa2.otherdomain.org.
40 gamma.mydomain.com.
[root@gamma ~]# host `gamma.mydomain.com`
-bash: gamma.mydomain.com: command not found
I was a bit confused by this last request as the backtick in bash is reserved as "run command in backticks and sent output here" like
for i in `cat /etc/hosts`; do echo $i; done
in a simple shell script...
but if I do a single tick:
[root@gamma ~]# host 'gamma.mydomain.com'
gamma.mydomain.com has address 22.33.44.55 (right address in lookup, but this isn't the host domain I can't find... the mx records for all mxes for that domain dig just fine. again, as I stated, this all works perfectly, I've been maintaining my own dns on Bind 9 for a long time now. I've done all the above tests and they all succeed just fine. The only other option I can think of that could be failing is that postfix may run in a chroot jail and the jail doesn't have something it needs... I just don't know if zimbra does that or not, and I really love the massively useless vague error that postfix throws. The email error I get as the sender is even more cryptic:
Here it is in its entirety:
This is the mail system at host gamma.mydomain.com.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<pdavis@otherdomain.org>: otherdomain.org
?????
~Phil