Setting up POP3 server

[Nicklas]

Hello
I want my members to have a email adress with my domain (kristenbert.mine.nu)

But how do i set up the pop3 server i Mercury?

I have installed a webmail script at kristenbert.mine.nu/index.php
and when im try to log in i get..

Fatal error: Call to undefined function imap_open() in C:\Xampp\xampp\htdocs\connect.php on line 63
I guess that because i dont have a POP3 server..

I searched for this but didnt find anything that could help me..