There is no MaxConCatMsgs setting for SMS Transport - GSM Modem. I guess I can just make the change in registry directly.
I'm running the demo version (advanced) for evaluation. I have experienced SMTP problems where the ActiveSMS email gateway service must be restarted. SMTP test also fail before restarting service. After a restart cached messages are forwarded to my Exchange server. I have enabled logging and will forward the log next time problem appear. Messages are available in incoming textfile log before performing the restart.
All in all, a very nice piece of sw when working!