The Post Office on NAS 2 Sigonella is conveniently located inside the Fleet Mail Center. The Post Office provides mail receipt and mailing services, sell of United States Postal Service money orders and postage stamps, change of address processing for patrons, mail directory-locator services, and USPS claims and inquiry services. In addition, the Fleet Mail Center on NAS 2 provides a pick-up point for accountable mail and official mail services and is open Monday through Friday 0800-1700 and Saturday 0800-1600.
Only U.S. currency is accepted at the Post Offices; however, you may use personal checks for the exact amount of purchase and major credit cards and bank debit cards. Money orders can be purchased for only 40 cents each, but a single money order can not exceed $1,000. Only cash and debit cards are accepted for purchasing money orders. You may use traveler’s checks to purchase most services, provided those purchases total at least half the amount of the check. As an authorized military postal service patron, you are responsible to inform all correspondents of your correct mailing and forwarding address prior to leaving
your present duty station. You should obtain your new address from your sponsor and notify all your correspondents at least six to eight weeks prior to checkout. Do not include the country or base name in your address under any circumstance. Doing so will only create delays and your mail could be processed through the Italian postal system and would be subject to customs inspections and fees. Your new address should contain all of the following information:
FULL NAME,
PSC and CORRECT BOX NUMBER
FPO AE and CORRECT ZIP CODE
An example would be:
Timmy Rollins
PSC 812 Box 9999
FPO AE 09627- 9999
It currently takes an average of seven to ten days for a first class letter or priority parcel to reach the States.
Source: Navy.mil Website