JavaMail
JavaMail is a Java API used to send and receive email via SMTP, POP3 and IMAP. JavaMail is built into the Java EE platform, but also provides an optional package for use in Java SE.
The current version is 1.5.5, released in December 2015. Another open source JavaMail implementation exists - GNU JavaMail - while supporting only version 1.3 of JavaMail specification, it provides the only free NNTP backend, which makes it possible to use this technology to read and send news group articles.