Totally lost - where do I go now?

[squaresphere]

After running the installer and creating config files, I open the index.php in the main folder and see three fields: user name, password, server.
What should I enter for those? Suppose I could put the user name and password of one of the existing users on the POP/SMTP server, but what should I put in the server field is a mystery to me.
If I need to RTFM, please point me in the right direction, appreciate your help.

[rosali]

Roundcube is an IMAP web client application. POP3 protocol is not supported. You configure it the same way as any desktop email client. Enter your access data to your IMAP account ...