How does mail delivery work?

Question

This might be a silly question, but my friend and I are having a conversation about mail delivery.

So, my question is how does the mail work? Does it only travel during the day? Or does it travel over night from distribution points? Does it travel overnight to the local post office and then they obviously deliver to our homes from that point. But what about to the post office.. does it get delivered overnight?

Thanks in advance.

Answer 1

Mail moves 24 hours a day!  All mail is brought to a centralize mail facility, usually called a GMF  

(general mail facility) or a P&DC (processing and delivery center).  Mail is taken from the truck by a  

human and dumped onto a belt where it is examined for postage and then cancelled.  Extra large items  

are cancelled by hand, but most items are moved around by machine via instructions listed on a  

barcode.  Most pieces of mail end up with 2-3 barcodes on them.  Mailers that want their mail to move  

really fast pre-barcode their mail.  Pre-barcoded mail is sorted all the way down to route sequence  

order, all by machine.  Trays of mail are then sent to the individual towns in a reverse bicycle spoke sort  

of design.  Missorts are then corrected and the Letter Carrier delivers the mail, or Clerk sorts it to a PO  

Box.  Delivery time for first class and priority mail is 2-3 days.  Express mail is guaranteed overnight  

within the continental US.

Answer 2

It travels 24 hours a day.  it goes from one General Mail Facility (GMF) to another till it reaches the destination GMF.  Than it goes locally. It arrives at the local post offices around 4AM.  Sorted to the different routes, where the carrier takes out on his reg. Route...