Domestic       International    
US Postal Service
     
US Postal Service
   
First Class
May take up to 3 days The least expensive, most immediate way of mailing postcards, letters, and large envelopes.Mail can weigh up to 13 ounces; for heavier items, use Priority Mail  
First Class
zonal The most economical way to send letters, small packages, postal cards, printed matter, and small packets 4 pounds and under, worldwide.
Media Mail
May take up to 9 days

Media Mail is used for books, film, videotapes, and computer-recorded media like CDs and diskettes. Media Mail cannot contain advertising.

Up to 70 lbs. Max.

 
Priority Mail
zonal Priority Mail International (PMI) is an airmail service that provides customers with a reliable and economical means of sending correspondence and merchandise up to 70 pounds to over 190 countries and territories worldwide.
Priority Mail
May take up to 5 days Delivery to all U.S. addresses, including PO boxes and military addresses.
Up to 70 lbs. Max.
 
United Parcel Service
   
United Parcel Service
           
       
Federal Express
   
Federal Express
           
            * more options may be added  in the future