Alrighty, bear with me as I'm still a little new to this stuff.
Release 5.0.9 FOSS on Ubuntu 8.0.4
Everything has been working since I set this up month ago. Send and receive just fine. I'm testing Zimbra. Monday I tried renaming the domain using "zmprov -l rd duratechind.com duratechindustries.net". That worked, and I was able to send and receive just fine. Then yesterday I renamed it back to what it was, and now I can't send e-mail to one particular domain. E-mail to lwinstead(at)daktel.com get's deferred with the error "lost connection to inboundmail2.daktel.com[18.104.22.168] while sending rcpt to".
I read lots on the forums about not being able to send out at all, but I AM able to send out to other domains, just not that one. Can someone help me figure out how to diagnose this?
By the way, according to what I've seen, my /etc/hosts file is fine, /etc/resolv.conf is fine, and the dig commands come back legit. The "host `hostname`" command has never worked as expected, but even still I have been and still am able to send and receive to other domains. Argh.