class Net::SMTP

def do_helo(helo_domain) 

def do_helo(helo_domain)
  res = @esmtp ? ehlo(helo_domain) : helo(helo_domain)
  @capabilities = res.capabilities
rescue SMTPError
  if @esmtp
    @esmtp = false
    @error_occurred = false
    retry
  end
  raise
end