posting vs voicemail

posting

noun
  • A message posted to a computerized bulletin board, a newsgroup, a blog, etc. 

  • The place where a soldier or airman is posted for duty; the time spent there. 

  • The action of the verb to post. 

  • An item inserted into a register, ledger or diary. 

voicemail

noun
  • An individual message on such a system. 

  • A computerized interactive system for storing, processing and reproducing verbal messages left through a conventional telephone network. 

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