No. Although there are some components in Xeams that are based on open sourced technologies, the main email engine is not open sourced. Similarly, the spam filtering engine is also designed by our engineers from ground up.
Apache Derby - A relational database that is used for reporting purposes
Why not make Xeams open-source?
Xeams uses a proprietary engine to filter spam/junk. Professional spammers are constantly seeking new techniques to avoid getting caught. Using an open source solution to fight spam may result in compromising the algorithms that play a key role in blocking these messages. Therefore, it is best not to use an open-source solution when it comes to blocking junk messages.