[Pete from Shawnee Mission]

Dr. When a letter is initially processed there is a postal clerk that sits at a coding machine and types in address information that will be bar coded on the front of your letter under the address. Then it gets sent to the big sort machine and is sorted into bins that get sent to regional postal centers for further sorting and distribution.

Might be more information here. I think that the front of the letter is photographed but I suspect that you have to be Law enforcement to try to access this info. (Ricin sent to the President in a letter for example.) Good luck, I hope they find or deliver your letter! Might be more info in one of these links.

https://www.gocomet.com/blog/usps-tracking-number/

https://www.letter-track.com/

[Runner4life]

There are no clerks sitting at a machine typing in addresses...that went away years ago...The old LSM clerk is long gone...it is all automated....all letter mail gets dumped on a conveyer that then gets sorted by machine and yes..photographed....letter size mail..not magazines etc