[Serusers] sipsak

Hello, I want to send a SIP message with sipsak to ser (running on the same server!!). I do it with: sipsak -s sip:192.168.1.222:5061 -f file.txt But the message doesn't reach the ser-server. If I send it with sipsak -s sip:localhost:5061 -f file.txt ...the message reaches the server, but with the error message: CRITICAL: invalid sendtoparameters one possible reason is the server is bound to localhost and attempts to send to the net 10(3681) msg_send: ERROR: udp_send failed 10(3681) ERROR: t_forward_nonack: sending request failed Does anybode know what could be the reason? Thanks! Sebastian