Currently, there are not many other stations that I exchange cards with, and I also have plenty of time, so there are rarely long delays in sending out QSL cards. From the moment I agree to apply for a card until it is shipped, it usually takes only one or two days. Therefore, I have never recorded the process of sending QSL cards, but I have created an Excel spreadsheet where I manually enter the other station's callsign and address, which is not difficult at all.