mail vs send off

mail

verb
  • To send (a letter, parcel, etc.) through the mail. 

  • To arm with mail. 

  • To contact (a person) by electronic mail. 

  • To pinion. 

  • To send by electronic mail. 

noun
  • The postal service or system in general. 

  • The letters, parcels, etc. delivered to a particular address or person. 

  • The material conveyed by the postal service. 

  • Tax. 

  • A bag containing letters to be delivered by post. 

  • Electronic mail, e-mail: a computer network–based service for sending, storing, and forwarding electronic messages. 

  • A contrivance of interlinked rings, for rubbing off the loose hemp on lines and white cordage. 

  • A bag or wallet. 

  • A monetary payment or tribute. 

  • Rent. 

  • A trunk, box, or bag, in which clothing, etc., may be carried. 

  • Any hard protective covering of an animal, as the scales and plates of reptiles, shell of a lobster, etc. 

  • Armour consisting of metal rings or plates linked together. 

  • An old French coin worth half a denier. 

send off

verb
  • To send; to dispatch. 

  • To show someone a red card, and dismiss them from the playing area. 

  • To provide a celebration for someone who is leaving; give a sendoff. 

  • To emit; to emanate. 

noun
  • farewell party 

  • funeral or memorial service 

How often have the words mail and send off occurred in a corpus of books? (source: Google Ngram Viewer )