The State Department advises U.S. citizens overseas to exercise increased caution because of increased tensions around the world and the potential for terrorist attacks, demonstrations, or violent actions against U.S. citizens and interests.
One self-addressed “Japan Post LetterPack envelope”
LetterPack LIGHT: 370 yen, traceable, signature not required
LetterPack PLUS: 520 yen, traceable, signature required
For persons using an APO/FPO address, bring one self-addressed envelope that will be mailed via Military Postal Service (MPS). Please note that MPS envelopes are not trackable. The Embassy cannot mail MPS envelopes using tracking numbers or by registered/certified mail.