Shalom,
1) Squirrelmail requires an imap server running on port 143. Make sure dovecot is installed then:
chkconfig --level 345 dovecot on
service dovecot start
Try again, checking the /var/log/maillog for errors.
Respond to the errors and report back.
Please post the error you are getting.
Also, for a test, shut down trend micro and see if its interfering with normal mail operations.
SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com