This script builds dovecot with support for SSL. As such, you must have
openssl installed - openssl-solibs is not enough in itself to meet this
requirement.  Additionally, dovecot will be compiled with POP3 support.
Unfortunately, dovecot does not have a man page at this time, so you'll
have to find your documentation elsewhere.  A few examples are included
in /usr/doc/dovecot-1.1.3.  The dovecot team maintains a wiki that may 
prove useful:  http://wiki.dovecot.org

You should create a dovecot user to run the login processes on your server.