Email open notification - ruby on rails

Question

If I will send 100 email to the registered user and I want to know if users open email or not

How can I do this using Ruby on Rails?

Answer 1

Short answer, You can't. Slightly longer answer You can't reliably.

Using something like VERP you can automate the the bounce processing, to get a fairly good idea if the far end mail server accepted the email. But after that all bets are off. You can't really tell what the email server did with it, (route it to junk/spam folder, put in inbox, silently drop it on the floor/bit bucket, etc..). You could enable read-receipt headers in your email, but that is client specific (and people like me eat/deny them). You can look into using a web bug, for example customize each email with an HTML file, that pulls a remote image, that has a unique id associated with it, but again client specific, most will not load remote images. So unless the email bounces there is no 100% reliable way to tell what happens to the email after it leaves your server.