Definitions of mail:

• noun:   a conveyance that transports mail
• noun:   the system whereby messages are transmitted via the post office

  Example: "The mail handles billions of items every day"

• noun:   the bags of letters and packages that are transported by the postal service
• noun:   any particular collection of letters or packages that is delivered

  Example: "Your mail is on the table"

• noun:   (Middle Ages) flexible armor made of interlinked metal rings
• verb:   cause to be directed or transmitted to another place

  Example: "I'll mail you the paper when it's written"

• verb:   send via the postal service

  Example: "I'll mail you the check tomorrow"

• name:  A surname (very rare: popularity rank in the U.S.: #50636)