Sms arrived but not placed in incoming sms folder

I've started to test Boomerang EMIX 5.0 library and I sent sms to Mobile Phones through TCP/IP on network T-Mobile. The sms has arrived successful but it wasn't placed in the folder Incoming Sms on the phone. When it has arrived i got a question to save or not. If answer is no, then i could not open it anytime, because it wast saved in the incoming sms folder. The effect is then same on any other type of phone.

What could be the problem?

Check message class

The message was received probably as display-only. Check message class (MCLs param) when TEMIClientX.Submit() is called. Related constants:

  mclDisplay = 0; // class 0
  mclME = 1;      // class 1
  mclSIM = 2;     // class 2
  mclTE = 3;      // class 3