jSieve is a Java implementation of the Sieve mail filtering language defined by RFC 3028. Sieve is an extensible mail filtering language. Its limited expressiveness (no loops or variables and no tests with side effects) allows user created scripts to be run safely on email servers. Sieve is targeted at the final delivery phase (where an incoming email is transferred to a user's mailbox). jSieve is implemented as a language processor that can be plugged into any Internet mail application to add Sieve support.
GreenMail is a suite of email servers for testing purposes and sandbox development. It supports SMTP, POP3, and IMAP (including SSL) and can be embedded into any Java application or unit test. The GreenMail Service (SAR) extension runs as a JBoss embedded developer mail server sandbox, manageable via JMX.
IP*Works! is a comprehensive suite of more than 40 native Linux class libraries for Internet development. It is a robust framework of enterprise-class tools, enabling rapid integration of any major Internet protocol or technology, including FTP, HTTP, SMTP, POP, IMAP, SNMP, LDAP, DNS, RSS, SMPP(SMS), XMPP (Jabber), SOAP, and WebDav. It includes source code for compilation on various Unix platforms, a framework for Objective-C (Cocoa) Mac OS X development, and native PHP extensions.
IP*Works! SSL adds SSL security, digital certificate generation, and certificate management capabilities to the base IP*Works! Linux class libraries. It supports secure implementations of every major SSL- enabled Internet protocol, including FTPS, HTTPS, SMTPS, POPS, IMAPS, LDAPS, SMPPS, XMPPS (Secure Jabber), SOAPS, and WebDavS.
Java SMTP Mail Component provides an easy API to send email from an application. The API has option to send emails directly to the recipients mail server without a relaying mail server. Plain authentication is supported for mail server authentication. Mail attachments are supported using MIME.