What is the meaning of mailing?

noun

• Mail sent by a sender at one time.
  • usage: "the candidate sent out three large mailings"
• The transmission of a letter.
  • usage: "the postmark indicates the time of mailing"
  • synonyms: posting

verb

• Send via the postal service.
  • usage: "I'll mail you the check tomorrow"
  • synonyms: mail, get off
• Cause to be directed or transmitted to another place.
  • usage: "send me your latest results"; "I'll mail you the paper when it's written"
  • synonyms: mail, post, send