code: public MailMessage defaultFrom(String email, String name) {
  
  		if (StringUtils.isNullOrEmptyTrimmed(fromEmail)) {
  			from(email, name);
  		}
  
  		if (!StringUtils.isNullOrEmptyTrimmed(email) &&
  		    StringUtils.equals(fromEmail, email.trim(), true) &&
  		    StringUtils.isNullOrEmptyTrimmed(fromName)) {
  			from(email, name);
  		}
  
  		return this;
  	}
docs: Sets from email address only if not already set
  
  @param email target email address
  @param name  target name associated with email address
  @return mail message