code: func (m *MailYak) fromHeader() string {
  	if m.fromName == "" {
  		return fmt.Sprintf("From: %s\r\n", m.fromAddr)
  	}
  
  	return fmt.Sprintf("From: %s <%s>\r\n", m.fromName, m.fromAddr)
  }
docs: // fromHeader returns a correctly formatted From header, optionally with a name
  // component.