Simple Java Mail is the simplest to use lightweight mailing library for Java, while being able to send complex emails including authenticated socks proxy(!), attachments, embedded images, custom headers and properties, robust address validation, build pattern and even DKIM signing and external configuration files with property overriding. Just send your emails without dealing with RFC's.

The Simple Java Mail library is a thin layer on top of the JavaMail smtp mailing API that allows users to define emails on a high abstraction level without having to deal with mumbo jumbo such a 'multipart' and 'mimemessage'.

ConfigLoader.loadProperties("simplejavamail.properties"); // optional default
ConfigLoader.loadProperties("overrides.properties"); // optional extra

Email email = new Email();

email.addRecipient("lollypop", "lolly.pop@somemail.com", Message.RecipientType.TO);
email.setReplyToAddress("lollypop", "lolly.pop@othermail.com");
email.addRecipient("C. Cane", "candycane@candyshop.org", Message.RecipientType.TO);
email.addRecipient("C. Bo", "chocobo@candyshop.org", Message.RecipientType.CC);
email.setSubject("hey");
email.setText("We should meet up! ;)");
email.setTextHTML("<img src='cid:wink1'><b>We should meet up!</b><img src='cid:wink2'>");
email.addEmbeddedImage("wink1", imageByteArray, "image/png");
email.addEmbeddedImage("wink2", imageDatesource);
email.addAttachment("invitation", pdfByteArray, "application/pdf");
email.addAttachment("dresscode", odfDatasource);

email.signWithDomainKey(privateKeyData, "somemail.com", "selector");

new Mailer(
		new ServerConfig("smtp.host.com", 587, "user@host.com", "password"),
		TransportStrategy.SMTP_TLS,
		new ProxyConfig("socksproxy.host.com", 1080, "proxy user", "proxy password")
).sendMail(email);

Simple Java Mail is available in Maven Central:

<dependency>
    <groupId>org.simplejavamail</groupId>
    <artifactId>simple-java-mail</artifactId>
    <version>4.1.2</version>
</dependency>

v4.1.2 (07-Nov-2016)

• #52: bug fix for windows / linux disparity when checking socket status
• #56: bug fix for IOException when signing dkim with a File reference

v4.1.1 (30-Jul-2016)

• #50: bug fix for manual naming datasources

v4.1.0 (22-Jul-2016)

• #48: Added programmatic support trusting hosts for SSL connections
• #47: Honor given names, deduce extension from datasource name, and more robust support for parsing mimemessages

v4.0.0 (05-Jul-2016)

• #41: added support for fast parallel batch processing
• #42: added support for config files
• #43: removed logging implementation dependencies from distribution and documented various sample configs
• #39: simplified and renamed packages to reflect the domain name of the new website: simplejavamail.org
• #38: added support for anonymous proxy
• #38: added support for authenticated proxy

NOTE: All packages have been renamed to "org.simplejavamail.(..)" NOTE: Switched to Java 7

v3.1.1 (11-May-2016)

Major feature: DKIM support!

• #36: Added proper toString and equals methods for the Email classes
• #33: Added support for DKIM domain key signing

NOTE: this is the last release still using Java 6. Next release will be using Java 7.

v3.0.2 (07-May-2016)

• #35: added proper .equals() and .toString() methods
• #34: Fixed bug when disposition is missing (assume it is an attachment)
• #00: added findbugs support internally

v3.0.1 (29-Feb-2016)

• #31: Fixed EmailAddressCriteria.DEFAULT and clarified Javadoc

v3.0.0 (26-Feb-2016)

• #30: Improved the demonstration class to include attachments and embedded images
• #29: The package has been restructured for future maintenance, breaking backwards compatibility
• #28: Re-added improved email validation facility
• #22: Added conversion to and from MimeMessage. You can now consume and produce MimeMessage objects with simple-java-mail

v2.5.1 (19-Jan-2016)

• #25: Added finally clause that will always close socket properly in case of an exception

v2.5 (19-Jan-2016)

• #24: Updated dependencies SLF4J to 1.7.13 and switched to the updated javax mail package com.sun.mail:javax.mail 1.5.5

v2.4 (12-Aug-2015)

• #21: builder API uses CC and BCC recipient types incorrectly

v2.3 (21-Jul-2015)

• #19: supporting custom Session Properties now and emergency access to internal Session object.

v2.2 (09-May-2015)

• #3: turned off email regex validation by default, with the option to turn it back on
• #7: fixed NullPointerException when using your own Session instance
• #10: properly UTF-8 encode recipient addresses
• #14: switched to SLF4J, so you can easily use your own selected logging framework
• #17: Added fluent interface for building emails (see manual for an example)

v2.1 (09-Aug-2012)

• fixed character encoding for reply-to, from, to, body text and headers (to UTF-8)
• fixed bug where Recipient was not public resulting in uncompilable code when calling email.getRecipients()

v2.0 (20-Aug-2011)

• added support for adding open headers, such as 'X-Priority: 2'

v1.9.1 (08-Aug-2011)

• updated for Maven support

v1.9 (6-Aug-2011)

• added support for JavaMail's reply-to address
• made port optional as to support port defaulting based on protocol
• added transport strategy default in the createSession method
• tightened up thrown exceptions (MailException instead of RuntimeException)
• added and fixed JavaDoc

v1.8

• Added support for TLS (tested with gmail)

v1.7 (22-Mar-2011)

Added support for SSL! (tested with gmail)

• improved argument validation when creating a Mailer without preconfigured Session instance

known possible issue: SSL self-signed certificates might not work (yet). Please let me know by e-mail or create a new issue

v1.6

Completed migration to Java Simple Mail project.

• removed all Vesijama references
• updated TestMail demonstration class for clarification
• updated readme.txt for test run instructions
• included log4j.properties

v1.4 (15-Jan-2011)

vX.X (26-Apr-2009)

• Initial upload to Google Code.