It is not envelopes that are postmarked (franked), it is the stamps on the envelopes (so that they can not be used twice). Therefore they are franked when fist processed in the sorting office.
yep! unless you have franked dividends
Frank, "He was frank with me"
The franked letter has the frank printed on it. This frank includes a unique serial number of the machine and/or the initials of the franking machine user, and/or a postal license number that can be traced back to the user.
The answer is an envelope. It contains a letter.
Envelope is a noun.
It does
The word is "envelope" (which usually holds only one letter).
on the envelope.
This envelope is like the window envelope,but the window opening is uncovered (an uncovered address panel).
The prepositional phrase in the sentence is "on the envelope".
The possessive form for the noun envelope is envelope's.Example: The envelope's flap wasn't sealed.