Yes, I knew mendelson opensource AS2 software for quite some time, but I have only discovered their on-line mendelson AS2 test server last Friday. Finally, a way to "independently" test my code, and guess what, it works! - after the correction of one small bug (see line #35).
Go to http://babelas2.googlecode.com/files/BabelAS2.v0.01.zip to download the version 0.01 of BabelAS2, which is pre-configured to send messages to the mendelson AS2 test server.
To monitor the data entries on the mendelson AS2 test server, just point your browser to http://as2.mendelson-e-c.com:8080/webas2 with user: guest and password: guest
Thanks to the mendelson team!