Packages 
Package Description
com.sun.mail.auth
This package includes internal authentication support classes and SHOULD NOT BE USED DIRECTLY BY APPLICATIONS.
com.sun.mail.handlers
This package includes internal data handler support classes and SHOULD NOT BE USED DIRECTLY BY APPLICATIONS.
com.sun.mail.iap
This package includes internal IMAP support classes and SHOULD NOT BE USED DIRECTLY BY APPLICATIONS.
com.sun.mail.imap
An IMAP protocol provider for the Jakarta Mail API that provides access to an IMAP message store.
com.sun.mail.imap.protocol
This package includes internal IMAP support classes and SHOULD NOT BE USED DIRECTLY BY APPLICATIONS.
com.sun.mail.pop3
A POP3 protocol provider for the Jakarta Mail API that provides access to a POP3 message store.
com.sun.mail.smtp
An SMTP protocol provider for the Jakarta Mail API that provides access to an SMTP server.
com.sun.mail.util
Utility classes for use with the Jakarta Mail API.
com.sun.mail.util.logging
Contains Jakarta Mail extensions for the Java™ platform's core logging facilities.
javax.annotation
This package defines the common annotations.
javax.annotation.security
This package contains the security common annotations.
javax.annotation.sql  
javax.mail
The Jakarta Mail API provides classes that model a mail system.
javax.mail.event
Listeners and events for the Jakarta Mail API.
javax.mail.internet
Classes specific to Internet mail systems.
javax.mail.search
Message search terms for the Jakarta Mail API.
javax.mail.util
Jakarta Mail API utility classes.
javax.security.auth.message
This package defines the core interfaces of Jakarta Authentication.
javax.security.auth.message.callback
This package defines callback interfaces that may be used by a pluggable authentication mechanisms (aka message authentication modules) to interact with the container (aka message processing runtime) that invoked the module.
javax.security.auth.message.config
This package defines the interfaces implemented by Jakarta Authentication compatible configuration systems.
javax.security.auth.message.module
This package defines the interfaces implemented by Jakarta Authentication compatible authentication mechanisms.