Java Enterprise Best Practices

Use Secure Protocols

Many mail servers now support Secure Sockets Layer (SSL) encryption for particular protocols (including SMTP, POP, and IMAP). If your server supports SSL, your JavaMail application can use it as well, reducing the likelihood of third parties eavesdropping on your communications. To do this, you need to create a JavaMail Session object that uses the Java Secure Socket Extension (JSSE) system, which is included in Java Development Kit (JDK) 1.4 or is available as an add-on for earlier Java 2 implementations.

To use JSSE with a particular protocol, you need to install the JSSE provider according to the instructions included with the JSSE installation. You can then create an SSL-aware session by setting the following three properties within the Session objects.

Property	Value
mail. protocol socketFactory.class	javax.net.ssl.SSLSocketFactory
mail. protocol socketFactory.fallback	true if the connection should resort to non-SSL if the server does not support SSL; false otherwise
mail. protocol socketFactory.port	The remote port for the new socket factory

You will also have to set the default port for the protocol if it is not the standard port for the protocol.

If the remote server uses a server certificate not supported by the JSSE implementation, you will need to add the remote certificate to your local set of trusted root certificates. See the JSSE documentation for more information.