title: Max character limit for email address
body: <p>I am sending an email address value to a third party service. I have following regex to validate email addresses: </p>
  
  <pre><code>`^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,})$`
  </code></pre>
  
  <p>but suppose someone tries to send as email address:</p>
  
  <pre><code>'WQWQQWWQQWQWWQWQQWW@WEOIWEOIEWOIEWIOWEIOEWIOEWPIOWEPOIWEPEWIOPIOWEOIWEOIEWIOWIOEWIOPEWIOPWIOEPIOWPEIOEWOIEWOIPIOEW.COM' 
  </code></pre>
  
  <p>this address is valid and then I get error in response object from the service. 
  My question is, what can be the possible maximum character limit for the domain part?</p>