code: def fetch_plaintext_by_subject(self, email_name):
          
          if not email_name:
              raise EmailException("Subject cannot be null")
  
          results = self.__imap_search(SUBJECT=email_name)
          sources = self.fetch_plaintext(results)
  
          return sources
docs: Get the plain text of an email, searching by subject.
          @Params
          email_name - the subject to search for
          @Returns
          Plaintext content of the matched email