Expedited Mail Service is the fastest, most reliable, and most economical way to send mailable matter overnight. Expedited Mail is used for items that require next day delivery. This is the only class of mail with guaranteed overnight delivery. If the Postal Service fails to meet next day guarantees, the mailer receives a full refund. Do not use Expedited Mail on friday unless you know that someone will be there to accept it on saturday.
Postage varies for each piece by weight.
Return Receipts are available upon request. The unmodified term Standard Mail applies to both. Mailers may find it more practical to send letters weighing 12 ounces or less that qualify for standard mail-A at first rates. For information about non-profit rates, see the Bulk Mail Section of this guide. Any Standard Mail matter may be mailed at the parcel post rate.