PGP Portable is a solution for encrypting an external drive that could then be sent to another party, who would not need any software on their end to access the drive, just a passphrase. Unfortunately, it is not a product that is still being developed.
See below:
http://www.symantec.com/docs/TECH179156
PGP Portable has already entered the last phase of support life. Technical support would be very limited in assisting you if there is an issue, and I would not recommend using it as a long-term solution.
PGP Zip funtionality includes self-decrypting archives, which can be sent to a third party and decrypted with no special software, just a passphrase. The file will be an executable, so to send it by email reliably, you would need to change the file extension and have the other party change it back on receipt of the file, but other than that, it works for end users without PGP installed.
For centralized management of policy and keys, you would need to set up a Symantec Encryption Management Server. This is a soft appliance, with its own customized Operating System based on Cent OS. All of the administration is then handled over a web-based GUI.