The United States Postal Service is alive and well, even in the age of electronic mail. Sending email is faster, but you may still need to mail many letters, cards and packages the traditional way. The USPS has established regulations for the mailing of all items, whether personal or business. Postage rates are based on the size and weight of the item being mailed. The USPS will not deliver items without the proper amount of postage.

Standard Letters

The standard letter is rectangular and is at least 3 1/2 by 5 by .007 inches. It can be no larger than 6 1/8 by 11 1/2 by 1/4 inches or weigh more 1 ounce to qualify for first-class mail. The postage stamp required for a letter this size costs $0.44, as of October 2010. If the letter weighs more than 1 ounce, extra postage must be added.

Postcards

These cards are an inexpensive form of messaging. There is a standard rate for postcards of $0.28, as of October 2010, but to qualify for this rate, the cards must be rectangular and 3 1/2 by 5 by .007 inches thick. If the card does not meet these requirements, the USPS will classify it as a letter and will require a standard postage stamp.

Non-letters

Flats, as they are sometimes known, may be large envelopes, newsletters or magazines. The dimensions for non-letters are 6 1/8 by 11 1/2" by 1/4 inches. Because of the maximum size of a flat, it is possible to fit a lot of material into the package, but remember that weight also affects the rate.

Stamp Placement

Place all stamps in the upper right corner on the address side of the mailing piece. Do not overlap stamps. Each one must be clearly visible for the rate to apply. You may not reuse stamps.

Forever Stamps

Forever stamps are those sold at the current first-class mail rate for a single 1-ounce letter price. These stamps are good forever, regardless of future price increases. You can use them for single-piece mail only.

Stamp Payment

The USPS only accepts U.S. currency for postage stamps. Checks are acceptable for the amount of the purchase only.

Postage Meters

Businesses use postage meters are in lieu of stamps. A permit is required from the USPS to use metered mail for bulk mailings. The rate is lower than first-class postage. You can purchase a postage meter from the USPS, but there are other companies that sell them as well. It is up to the purchaser to buy the postage for the meter.

Computer Postage

You can now print postage from a computer, which can save you a trip to the post office. The USPS uses the Information-Based Indicia system. Some authorized providers are Pitney Bowes, Endicia Internet Postage and Stamps.com.