title: System.Net Sending mail to gmail
body: <p>I have an application using System.Net to send emails to users. A few days ago, we found that users using Gmail are unable to receive emails sent through the application, however, mails sent directly using Outlook are fine. This occurs with and without an attachment.</p>
  
  <p>Tested sending mails to Yahoo and Hotmail, and it is fine (through Outlook and the Application).</p>
  
  <p>We checked the error log and there were no errors found. </p>
  
  <p>Update: Found that it gmail recipients are receiving the email after some time  (delayed email, anywhere from 1hr to 24hrs).</p>