Can I get the source code for the JavaMail API implementation?
Starting with JavaMail 1.4.2, the source code for the JavaMail API Reference Implementation is available under the CDDL or GPL open source licenses in the JavaMail project at Kenai. You’ll need Mercurial to check out the source code. Previous releases of JavaMail are also available as part of Project GlassFish. See the mail module page at GlassFish for more details.