Title says it all
APART from them being unavailable/available for different types of mail (parcels, first class, express, priority, etc.) can anyone give me a concise explanation as to the difference between these three?
EDIT: if the difference between certified mail and delivery confirmation is that with certified the addressee signs for it wheras with delivery confirmation the postal carrier just reports it as delivered, then what’s the difference between certified versus delivery/signature confirmation combo?
Certified: A unique code number is assigned to that piece of mail, and the post office keeps a record of the fact that the item was delivered and signed for. If you want, spring for Return Receipt and you get a little green postcard sent back to you as notification. If not, use that code number to track the delivery online. Works on first class letters and Priority Mail.
Delivery Confirmation: Confirms time/date of delivery of that item. Works on many ‘types’ of mail, from letters to parcels.
Signature Confirmation: Make someone sign for the item and get a copy of the signature. Works on parcels too, unlike Certified.
It sounds like with Certified, it only works on letters or Priority Mail, and the post office keeps a record of the delivered item on file, as well as allowing you to opt for a Return Receipt postcard, which has the signer’s original signature on it. Delivery/Signature Conf. doesn’t seem like the post office keeps records of the signature/delivery, and you only get a copy of the signature, not an original, but it does work for more classes of mail.
The USPS gives a fairly clear summary explanation here.