Need to generate file winmail.dat (Transport Neutral Encapsulation Format - TNEF) with attachment in Java

Question

I want to generate file winmail.dat which in TNEF format with java. Is there any Open Source library which I can use to create TNEF file.

I found one

http://poi.apache.org/hmef/

but it is read only API for parse TNEF file.

Please let me know if there is any other API for Java or any other language by which I can reach my goal.