United States writer (born in 1923)
"The mailer, a prominent American novelist born in 1923, won several awards for his early works."
a person who mails something
"The mailer carefully placed the letter in the box before sealing it."
an advertisement that is sent by mail
"The company decided to send promotional mailers to every household in the neighborhood."
a container for something to be mailed
"The mailer arrived at my door containing several small packages ready for shipment."
One who sends mail.
"The dedicated mailer delivered every package to the correct address before noon."
A surname.
"The mailer family has lived in the village for three generations."
The word mailer is formed by adding the suffix -er to the noun mail. This construction simply indicates a person or thing that performs the action of sending mail.