CMS Packages
org.bouncycastle.cms: A package for processing RFC 3852 Cryptographic Message Syntax (CMS) objects - also referred to as PKCS#7 (formerly RFC 2630, 3369).
org.bouncycastle.cms.test: Regression tests for the org.bouncycastle.cms package.

S/MIME Packages
org.bouncycastle.mail.smime: High level classes for dealing with S/MIME objects (RFC 3851).
org.bouncycastle.mail.smime.examples: Example code demonstrating the use of the S/MIME package for a variety of uses.
org.bouncycastle.mail.smime.handlers: S/MIME handlers for the JavaMail API.
org.bouncycastle.mail.smime.test: Regression tests for the org.bouncycastle.mail.smime package.
org.bouncycastle.mail.smime.util
org.bouncycastle.mail.smime.validator

Streaming ASN.1 Packages
org.bouncycastle.sasn1: A library for parsing and writing ASN.1 objects using a streaming model.
org.bouncycastle.sasn1.cms
org.bouncycastle.sasn1.test