Hello,
green colour flag means the message is stuck in the outbound queue of your client system. Scroll to the right to jump to the queue monitor or check SMQ2. There may be several reasons for this:
1) You haven't registered queues on your system yet. This is done in SMQR, just register the queue which is stuck using wildcards like "XBTO*". Once this is done, message should be executed automatically.
2) Your queue is blocked by another message. Check that message and resolve the problem.
In 99% of all cases one of those will be the problem. It is easy to solve.
Regards,
Jörg