How to validate email address that actually exists using Rails

I know how to validate form using rails but I’m curious to know, How to validate an email address That actually exists Using Ruby on rails.
For example, “” it’s my email. So I’d like to check if it really exists or not.

I really need it. I hope you will help me.

Thank you very much

I feel your pain.
Some user just stubbornly don't accept that they got the wrong email address.

For such normal use case, I use Amazon SES as my transactional email sender.
They deliver bounce reports in various channel (including HTTP) via their SNS service.

See more info about it here:

Once you got the bounce report, which contains the email address, you'll know that the email does not exist.

This works great in every project I encountered so far. It has a little acceptable limitation though, you can't tell unless you try sending an email.

If you design your application in a way that users can resend confirmation emails. You'll able to provide a nice and friendly notice there.