I noticed that mendeslon AS2 has a JMS interface which is an API to
communicate with it.
AS2 1.1 b29 is at JORAM 5.2.5 (JMS provider) http://joram.ow2.org/
Specs here
http://java.sun.com/products/jms/docs.html
From this post
http://community.mendelson-e-c.com/node/431
It looks like you would use
JMS access user with write access is "as2user", the password is
"messagequeuepasswd".
Also you would need to send an Object of
de.mendelson.comm.as2.jms.SendOrder.
"the message must be wrapped in this object to be accepted.
There is a class called JMSMessageSender, please have a look into it
for further information"
And knowing nothing else, it looks like you could use python PyHJB
http://hjb.python-hosting.com/ to communicate to mendelson AS2.
-Michael