Hi

I have 2 email server using MTA as sendmail. One mail server is on network and other is also on network but is exposed to internet with an ISP. When I send any email from my network sendmail server to internet send mail server the relay it is using is that of ISP and not the local IP.

here is a better explanation
Internet Sendmail: IP:192.168.10.13 along with ISP:x.x.x.74
Network sendmail: IP: 192.168.10.44

when i send any email to 192.168.10.13, it is using x.x.x.74 as relay and not 192.168.10.13. I have added an an entry of domain and address mapping in /etc/hosts of both computers. Why is it not working, any clues/pointers that can help me out. Do I need to edit any other file?

Wait, did you say you're editing your /etc/hosts file? If that's the case, that's most likely your problem. MTA's need MX records to properly work. Do you have proper MX records for each mail server?

Thanks for yours reply. The servers are on the network so do the MX record matters? if yes then how do I check whether the MX records are setup properly or not?