As a noun:
* I received a letter in the mail today.
* The mail carrier delivers packages every day.
* I need to go to the post office to send some mail.
As a verb:
* I mailed the package yesterday.
* Please mail me a postcard from your vacation.
* They mail out newsletters every month.
In a phrase:
* The mail order company offers a wide variety of products.
* I sent an email, but I also sent a letter through the snail mail.
* She got a mail-in rebate for her new phone.