When you receive digitally signed messages, you can validate the signer's digital ID (certificate) to determine that no forgery or false representation has occurred. To have the sender attach a digital ID to a message, ask him or her to send you a digitally signed e-mail message.
The digital ID is now stored with your contact entry for this recipient. You can now send encrypted e-mail messages to this person.
To view the certificates for a contact, double-click the person's name, and then click the Certificates tab.
To view the certificates for a contact, in the Contacts folder, double-click the person's name to open the contact, and then click the Certificates tab.