I sent a mail a week ago with regular USPS postal service. It was supposed to be delivered on Saturday, but it has not been delivered yet. Unfortunately, I do not have a tracking number. I was wondering what are the chances for it to be lost vs delayed; and how long I should wait to resend another mail instead.
I don’t think you’ll have much luck without a tracking number. In my experience, mail that is ‘lost’ is usually misdelivered, so it’s up to the misdeliveree to send it back, or if it’s a neighbor, to slide it in your box. If they send it back to the sender, and they resend it, it will probably take over a week with all the handling. If it was not something critical, I’d wait another week or so. If it is, I’d go ahead.