To install fetchmail, find out your distribution and proceed accordingly
SUSE Linux 12.1 x64
To install fetchmail under SUSE Linux 12.1 x64, open a console as root and enter
killall packagekitd yast -i fetchmail
fetchmail -p pop3 -u 131313 -v pop.gmx.net
Asks for a password and fetches the mail of user 131313 from the pop3 server pop.gmx.net.
To schedule fetchmail, e.g. to fetch your mail all 5 minutes, use cron. To make sure fetchmail knows your password, create a file in your home folder named .fetchmailrc like this:
poll your.provider.org user "yourusername" pass "yourpassword"