JavaMail 1.6
· This feature allows applications to interact with an external mail server by using the JavaMail 1.6 API, which provides common store and transport protocols, such as POP3, IMAP, and SMTP.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window javaMail-1.6-23.0.0.8.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.