DNS checks out, looked at the wiki but still cannot receive mail?!?!

[antimatter]

Ive installed zimbra on an ubuntu server. Seems to work great but I cannot receive mail unless i turn off dns lookups in zimbra. Then, i can receive mail fine but cannot send.
In looking at the zimbra wiki it states the steps to check your domain and server MX and A records with 'host -t mx' and 'host -t a'. We did these and additionally went to dnsreports.com and everything looks perfect. Is there something else we can check to see whats going on?
fyi in the zimbra admin console i can see the incoming emails being deferred because the connection is refused. Zimbra sits on the same physical box as the host the records are pointing to.
I would greatly appreciate any help.

Ryan

[phoenix]

It's difficult to tell what's causing the problem as you haven't posted any details.:( The words 'NAT router' & 'split-DNS' spring to mind as I don't have anything to go on, try searching the wiki. The fact you have to turn DNS lookups off/on is indicative that your DNS isn't correct.

[antimatter]

Thanks Bill. I will try with the details...let me know what you need.
If I leave dns enabled for the MTA I get this in the logs:
postfix/lmtp[32010]: A76D32B4728: to=, relay=none, delay=0, status=deferred (connect to {my ip} [ { my ip }]: Connection refused)
I have tried the wiki solution to change the zimbraMailTransport for this user. I have tried changing it to [myhost.mydomain]:7025 and [myexternalip]:7025 with no affect.
I can telnet to both ports 25 and 7025. I just dont get it.
If I disable dns them i can receive fine but cannot send ( makes sense ). Im wondering if I should setup local dns but that sounds odd. Why would I have to have a local dns to point the same server its sitting on????
Any help would be appreciated.

Ryan

[marcmac]

Repeat your telnet test, but telnet to the IP that DNS resolves the address to - simply telnetting to the hostname will not force DNS resolution.