Have you been waiting 4 days since he told you it was in the mail, or 4 days since your money arrived to him? In any event, it all depends on what your source's policies are. If he tells you that his turnaround time is anywhere from 8-30 days-- then you should expect to wait anywhere from 8-30 from when he receives the money. A lot of sources don't send with tracking numbers, but have delivery confirmation-- once again, what did your source tell you his policies were? So, to answer your question, it all depends, but in any event, 4 days doesn't sound like anything to worry about. Good luck and try to relax.