title: verify email opened
body: <p>once we send email from php using mail() function, is there any way to check either mail is open or not?</p>
  
  <p>may be any type of database insertion code in email..?</p>
  
  <p>or calling any function from website?</p>
  
  <p>any possibility.........</p>
  
  <p>i search on internet all the day but did't found any ans.</p>
  
  <p>Thanks</p>