How to set up Thunderbird on a LAN (not connected to Internet)
 

I have a LAN of dual boot systems - each system has Fedora 9 and Win XP/Vista.

How do I configure Thunderbird, sendmail, Firewall etc. so that users on different machines on the LAN can email each other?

For starters - Assume everyone is on Fedora for now.
The first machine has users root, A and B.
The second machine has users root, C and D.

- How does user A mail to user B?
- How does user A mail to user C?

PS - I have Samba up with the different Netbios-Names showing up in Nautilus File browser. How do I use the same machine names in the email addresses?

Thanks in advance for your help!

In a nutshell, set up the computers to have SMTP (I personally like Postfix) and POP3/IMAP (I personally like Dovecot) installed. If you want them to all email each other independently, then you will need at least SMTP installed on each computer, or do something like a relayhost. Then have your users on the LAN set up Thunderbird to connect to that SMTP and POP3/IMAP IP/hostname of the computer with SMTP and POP3/IMAP installed, which could be themselves.

SMTP = port 25/tcp
POP3 = port 110/tcp
POP3S = port 995/tcp
IMAP = port 143/tcp
IMAPS = port 993/tcp

Also make sure to update your DNS or local hosts file or NIS so that you can use hostnames and/or FQDN's to send mail. Otherwise you'd be stuck using IP address and your users might not remember all those numbers.