fedora core - 2.

i tried to access webmail by using
http://localhost/webmail/src/login.php
when i entered my username & password, the following error comes
error connecting to IMAP server:localhost. 111:connection refused

can the root user & other users created by using "adduser" access its mail thru this ??
everything is default. i have not touched sendmail, imap, postfix etc....
so, how to get rid of that error ????