I am trying to figure out the best and simplest way to use secure email with clients at my office. We are on exchange 5.5 here and the client is mailing from a relatively secure address.

I know that pgp is the major encryption and that I can have the client sign up for a certificate, but I get bogged down in all different information out there. I haven't a straightforward explanation yet....

Here's the bottom line. I need to be able to receive email from clients that is both secure and private. I need to be able to authenticate the email and its contents. Can anyone help out with some suggestions of products and/or steps to get this rolling?

It is for a business, but primarly it is to be able to authenticate [gloworange]incoming [/gloworange] emails.

Muchas Gracias!

Jennie