The problem is that something is already listening on these ports.

The following command will show you what's listening:

$ sudo netstat -lnp | grep 993

You will see a result similar to this:

tcp        0      0 0.0.0.0:993             0.0.0.0:*               LISTEN      2771/couriertcpd

The last column gives you the PID and name of the process bound to that particular port.

To unbind the process in this particular example, you would need to run the following command:

yum remove psa-courier-imap