Question : hmailserver sending but not receiving email

Good day, I've got kind of a weird problem.  I'll start with a bit of background on my setup.

Main Network my modem goes to a switch, the switch goes to my mail server running HMailServer (on it's own IP), and to my router (also with it's own IP) that then runs my internal network.

I had a backup hmailserver setup off site and MX records setup for both the primary and backup servers.  A few weeks ago I took my backup mail server offline as part of a move and have not yet gotten it set back up.  At that point everything was still working fine.  Last night ms update decided to install some updates and reboot my primary mail server.  Not a huge deal in and of it's self, except now I am not receiving any email.

I have run a bunch of tests, and this is what I found.

From any external email source (blackberry, gmail, etc.) to my internal email it is not delivered.  there is not error message bounced back as of yet (Just started testing an hour or so ago).  The mail server does not show that's it has processed the message.

From Internal to Internal you can send and receive.

From Internal to any external you can send and they will receive it.

I've double checked all my fire wall settings and they appear to be ok, and I've rebooted the server for good measure.  As a thought I contacted the company that controls my DNS records and had them delete the mx record for my backup server.  I'm hoping that when the server went down last night that messages started trying to get routed through the backup server.  As of yet when I do an mx lookup on my domain the backup IP is still listed.  Not sure how long t takes to replicate, or if that is even my problem.

Any insight would be appreciated.

Scott

Answer : hmailserver sending but not receiving email

check the MX entries from a seperate internet connection.

from a command prompt, type in nslookup -type=MX {domain name}

next thing to try would be to telnet to your e-mail server on port 25 from the internet.  
(don't use the IP address, use the hostname that is returned from your nslookup.)

If you've got connectivity, you will get a reply and you can type in helo and get an answer.  

If you get nothing, you've found your problem.