[Zope] RE: PGP Signed e-mails.

Hi, I am using ( hope to be) SSL for secure connections between customers and a server, what I would like to do is forward credit card transaction information from the Server to a machine behind a firewall at my place of business. I assume the best way to do this is to PGP encode an e-mail and send it to the machine behind the firewall. What I would like to know is this the best method? And secondly has anyone implemented functionality in zope to do this? Thanks, Brenton Bills.