title: Email verification using telnet fear of marked as spam
body: <p><strong>Problem Background:</strong>
  I have a 35K+ user members and growing fast. I am planning to migrate to Amazon SES service. Amazon SES has a criteria to reduce the quota or even terminate service based on bounce-back emails.</p>
  
  <p>I send promotional emails to my members. But the fear is that there are email address which are no longer exists so a fair possibility that Amazon SES notice me and take action to reduce or terminate my service. I need to make sure I have valid email address which do not disturb SES.</p>
  
  <p><strong>Possible Solution:</strong>
  To cope this problem I am planning to do the following procedure for each email address;</p>
  
  <p>Step1. Collect the MX record for the email domain.</p>
  
  <p>Step2. telnet to that MX domain</p>
  
  <p>Step3. Verify email address with the following pattern</p>
  
  <pre><code>EHLO my_domain_name
  MAIL FROM:&lt;my_valid_email@my_domain_name&gt;
  RCPT TO:&lt;email_to_verify@my_user_email_domain&gt;
  </code></pre>
  
  <p>I will verify the response after each command trigger such as email is valid if I receive 250 status after RCPT command</p>
  
  <p>Now what are the possible <strong>precautions</strong> I should care about to be not marked as SPAM or rejected by the remote server???</p>