I am now maintaining a Drupal module, mailcheck.

Here’s a short description below. Check it out.

Get fast, client-side suggestions for mistyped email addresses.

What is it?

An integration of mailcheck.js with forms in Drupal (supports user registration, webforms)

What’s it do?

Someone enters user@gmaul.com, mailcheck asks, Did you mean user@gmail.com?

Reduces Email Bounces

Kicksend reports of a 50% decrease in sign up confirmation email bounces. Try it out on Kicksend’s join form.