This plugin handles S/MIME signed and/or encrypted 
mails. You can decrypt mails, verify signatures or 
sign and encrypt your own mails.

WARNING: This plugin doesn't handle sign+encrypt and
encryption of multipart messages very well (yet).

It can be selected as the Default Privacy System in 
/Configuration/[Account Preferences]/Privacy and when 
composing a message from /Options/Privacy System

The plugin uses the GPGME library as a wrapper for GnuPG.

GPGME is copyright 2001 by Werner Koch <dd9jn@gnu.org>