title: how to check if it returns response code is "421"?
body: <p>How to check if response code is 421 because im trying to send email but connection sometimes get disconnect so it return 421 instead of 220</p>
  
  <p>ERROR </p>
  
  <pre><code> Expected response code 220 but got code "421", with message "421 
   Cannot connect to SMTP server 74.125.200.108 (74.125.200.108:587), 
   connect error 10060"
  </code></pre>