When opening the SMSManger the
SENT grid on the MESSAGES tab will
show the messages.
If the icon is red it is still
pending.
This might be because:
the receiver's cell is off,
the number does not exist or
the connection between the
SMSManger and PC from which it was
sent, is setup incorrectly.
Check if the SIM-card is working. You can test it by putting
the SIM-card in a cellphone and by sending an SMS from that cellphone.
If the icon is green the message has been sent.