Rails, SendGrid - Forwarding mailer-daemon emails to user

I have an application that allows users to send an invitation to a friend. Emails are being sent out using SendGrid. I am wondering if it's possible to forward the mailer-daemon emails back to the user in an event they type in an email address t开发者_开发知识库hat doesn't exist.

So for example a user enters in the email 'thisisnotreal@fakedomain1234.com' to send the invitation. I want to be able to notify the user that the email they have entered doesn't exist. Usually when you just send an email from an email client the server lets you know right away that the email is not able to be delivered. I am wondering if it's possible to do this as well through SendGrid.

Take a look at the event notification section of the SendGrid API. You can add a page to your application that accepts POST requests from SendGrid, and then you'll get event notifications in real-time.

When a bounce event is posted to that listener from SendGrid, you could then lookup the user that needs to be notified via the recipient email. If you don't have this relationship available in your local store, you could pass a unique argument to SendGrid at send time that contains information you can use for the lookup - unique arg information is included with event notifications. Then it's just a matter of taking the appropriate action required to notify your user - either with an email or via a notice on your website or a text message or whatever is best for your application.

This maintains asynchronous communication. You'll be alerted when something goes wrong without having to add blocking code, and you can send your users a nice branded message (using SendGrid, of course) rather than just forwarding a mailer-daemon response .