You can't. The only tracked mail is if you pay extra to have a tracking number on it.
Yes
Hogwarts doesn't exist, they have not sent you a letter which means it cannot be lost in the mail.
42 cent for an ordinary first class letter.
44 cents
A certified letter is a type of mail that requires the recipient to sign for it upon delivery, providing proof that it was received. This is different from regular mail, which does not require a signature and may not provide confirmation of delivery.
It depends. What is regular mail? UPS? Fed-Ex? Is it a letter? Or is it a package?
For a regular letter, two.
Current postage for a regular 1-oz. letter costs 44 cents.
Yes, lost undelivered mail can often be traced, depending on the postal service used. Most postal services have tracking systems that allow you to check the status of your mail using a tracking number. If the mail is not trackable, you can contact the postal service for assistance, providing details such as the sender and recipient addresses. However, the success of tracing lost mail can vary based on the service and the specific circumstances.
1 to 14 days or more
You can... but I wouldn't. It goes through machines whenever you put it in a regular envelope & if its not flat... it could rip it & your key could get lost somewhere. I used to work with the 1800askusps.
7-10 business days depending on the weather, regular mail.