Don't expect someone to write this for you.
You have a couple of steps to take. First, you
need to establish a dial-up connection - either
by exec()-ing a platform-specific program to do
this or by using a Java implementation of PPP
(or whatever the protocol your terminal server
expects). Second, open a socket to the server
and get your messages. By messages I assume
you mean e-mail, retrieved using something like POP -
if so you will have to connect a socket to the POP
server and communicate with it using the
expected protocol. There are third-party classes
available for both PPP and POP, you can use or you can write
your own. I suggest you look at the JavaMail forum
and FAQs for clues on using JavaMail to download
your messages.