Setting up linux as an email server

[Mettavihari]

I am setting up 3 linux mail servers to provide free email in Sri Lanka. 
and would like to have a bit help with my dial up connection.

I am running redhat4.2
have one machine connected to the net "metta.lk"
and have another 2 machines that should dial up and get mail
at regular intervals.

I have problems setting up the dialup connection,
and would like to have some help with that.

Jacob (Mettavihari)