- Checking signatures of received emails
- Decrypting received emails
- Sending signed and/or encrypted emails
- Creating new key pairs easily
- Optionally, caching your passphrase or using gpg-agent.
Although deprecated, the PGP/Inline method of signing or encrypting emails is still available, so you can switch to it for correspondents who still have older mail user agents that cannot handle the OpenPGP/MIME standard.
GnuPG and GPGME are required, http://www.gnupg.org/