If you have WEBppliance and Collaboration suite installed on the same server, when you remove Collaboration suite it will shutdown and disable all of the services (sendmail, httpd, ftp, etc).
You can use the command chkconfig to list all of the services and re-enable them by doing:
To re-enable do:
chkconfig --level 3 httpd on
Do this for all of the services that were disabled, then reboot your servers.