I don't think you want to exit the loop when you hit "i" - that would only send the message to the portion of the users whose socket was less than the sender.
I think something like this should work in the inner if statement:
...
{
// if the sending socket is equal to the socket receiving the message, don't send.
if(j != i)
send(j, recvbuf, bytes, 0);
}
...