Hi guys..


I have little bit experience on postfix mail server. I have to configure postfix mail server for my internal network. I have gone through the postfix documentation and tried to configure postfix and finally i m able to do the telnet 127.0.0.1.

Now I need some help in this regards as,

1] Is it possible to send and receive mails(internally) without DNS.
2] If it is possible then please let me know the steps for same.

Greetings!
Maybe I can shed some light on a few things;

Question 1:
"Is it possible to send and receive mails(internally) without DNS."

Yes, /etc/hosts is your friend in this case. However that only takes care of the UNIX/Linux hosts. For Windows, you'll have to take a copy of your /etc/hosts file and "Import LMHOSTS File".

Question 2:
"If it is possible then please let me know the steps for same."

After you've created an /etc/hosts file and passed it around to the hosts on the network, there shouldn't be a postfix-related change that you'll need to implement. Assuming, of course, that you're not trying to pass mail to another Mail Transfer Agent (MTA) like Exchange, Sun's Java Enterprise Management Message service, etc.

If you're attempting to experiment with other mail servers on different platforms, I would strongly suggest that you setup ISCs BIND (or another DNS service) somewhere on your LAN.

Doing that would also save you the trouble of manually updating your /etc/hosts file on ever single server, too. After all, not much may change on your LAN, but it can get very frustrating very quickly; especially if you're in the habit of setting up multiple IP addresses per host for various services....

Hope this helps!

Hi...xeleema,

Thanks for your response.

Can you please guide me to build internal DNS server for me(Specially only for MX).

For a really thorough guide to DNS, there's already a few really good resources out there;

If you're into books (the dead-tree kind), I *highly* recommend getting O'reilly's "DNS & BIND".

The Internet Software Consortium maintains a great Administrator's Reference Manual for DNS, too - They have one for each major release of their DNS software (which is found in most Linux distributions).

Keep in mind that with /etc/hosts, there's no "MX" equivalent. You'll almost certainly have to setup a DNS service on your network. In fact, I would recommend that you setup two systems with DNS, and have one be the master.

If you *really* want an exercise in Linux, read up on some of the virtualization software available for Linux (*cough* Xen *cough*). Then setup two virtual systems to host your DNS.

Have fun!