What is PGP?
PGP, or Pretty Good Privacy, is also known today as GPG. Its a widely used privacy tool that changed the world when it was introduced in 1991 by Phil Zimmermann, who paid a high personal price to bring it to the world. How Open PGP came to be is a fascinating story.
PGP uses a public key for encrypting a message, and a private key to decrypt. Before sending an encrypted message, you will first need to obtain the recipient's public key (and vice versa). Typical ways of sharing public keys is to just send it to someone in an in an e-mail, or to upload it to a public key server where Encryptomatic OpenPGP can find it automatically.
Encryptomatic OpenPGP for Outlook is compatible with popular implementations of Open PGP and GPG, including Enigmail.