postal

As an adjective postal

is relating to the collection, sorting and delivery of mail.

As a noun maildrop is

a place where postal mail is received and then forwarded to another address, used for anonymity or as a fixed address for somebody who is travelling.

As an adjective postal

is relating to the collection, sorting and delivery of mail.

As a noun mailpack is

(marketing) a collection of published, printed materials, and sometimes other objects, placed in a container (typically an envelope) and sent through the mail to a specific person or postal address.

As adjectives the difference between postal and nonpostal

is that postal is relating to the collection, sorting and delivery of mail while nonpostal is not postal.

As an adjective postal

is relating to the collection, sorting and delivery of mail.

As an adverb postally is

in terms of, or by means of, the postal service.