Are you running a firewall on the client or server? Make sure the commmunication port that you have configured for SEE is set to "allow" traffic.
Also if you plan to use optional HTTPS communication between Client Computers and the SEE Management Server, you
must install a server-side TLS/SSL certificate on the SEE Management Server, and provide a client-side TLS/SSL
certificate when prompted during installation of the SEE Management Server.
See page 21 in the Installation Guide for more info.
ftp://ftp.symantec.com/public/english_us_canada/products/symantec_endpoint_encryption/7.0/manuals/SEE-FD%207.0.6%20Installation%20Guide.pdf