code: func (m *MailYak) Send() error {
  	buf, err := m.buildMime()
  	if err != nil {
  		return err
  	}
  
  	return smtp.SendMail(
  		m.host,
  		m.auth,
  		m.fromAddr,
  		append(append(m.toAddrs, m.ccAddrs...), m.bccAddrs...),
  		buf.Bytes(),
  	)
  }
docs: // Send attempts to send the built email via the configured SMTP server.
  //
  // Attachments are read when Send() is called, and any connection/authentication
  // errors will be returned by Send().