This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Of or relating to a post office or mail service.

idiom. go postal Slang To become extremely angry or deranged, especially in an outburst of violence.

adj. Relating to the collection, sorting and delivery of mail.

adj. Belonging to the post office or mail service

Relating to the post or mails; belonging or pertaining to a mail service: as, postal arrangements; postal regulations; postal service.

Called post-cards in the United Kingdom.

n. A postal card or postal order.

adj. of or relating to the system for delivering mail

"Many in postal management are driven only by securing higher pay and bonuses."

post card   

postal note    postal card    postal tube    postal car    universal postal union    postal order   

post office    go postal    post    postally used   

bicoastal    coastal   

federal    municipal    post office    governmental    consular    maritime    wireless    naval    telegraphic    sanitary