If it were me, I'd start over, and follow the directions in the installation guide to the letter.
http://www.scalix.com/documents/Scalix_installation_Guide_113.pdf
Pay particular attention to the part on page 41 or so where it tells you exactly which packages to pick for a RedHat installation. If you follow those guidelines, you won't have missing httpd and you wont' have some IMAP and POP3 already running.
Good luck!