I have been a very active trader since I have joined and I am extremely close to 1000 positive feedbacks. (hope I don't jinx myself) I have had some glitches with the mail in the past and am always willing to resend items that were not recieved. What I have started to do recently is take my reciept from the post office and write a transaction number next to the address. It won't get the mail there if it doesn't show up, but it does supply a date, time group for when it was sent. When all of the reciepients have gotten their mail, I toss it. I usually have 10-25 transactions out at a time and I think this helps keep track of the status of my trades.