Chadley Wilson wrote:
Hi Sandy, and all
The firewall is pointing to our internal DNS, after a good look it is also running its own DNS, ie named. In /etc/resolv.conf I first point it to our internal dns and then to our ISP, removing the localhost entry.
At this point the Internet speed is greatly improved, So before removing the local host entry our top download speed would be about 476 bytes after removing it we are now getting up to 106KB
That smells like dns time-outs.
But the problem is that our mail to only one of a our branches does not route.
Then debug that route. What do the server logs show when you send mail to that problem server?
Now the mail server setup is a big mystery too, we are running a windows mail server on 172.100.1.21 and it forwards all the mail to our firewalls mail server exim on 172.100.0.1. Exim or the firewall then sends it out ?
Exim is sending the mail. Though I can't help you with any details on exim or sendmail.
I have asked the ISP to register an MX record for me for the mail server and I will move it into a DMZ. This should solve this unexplainable problem. Will let you know how it goes....
What does the log of the receiving server show when you try to send mail? Sandy