We do that, but I don't want our server sending a verification email to "taylor@gmail.con", it should fix that on the input field.
Just send a verification email...
https://mandrill.zendesk.com/hc/en-us/articles/205583217-Int...
Wouldn't integrating this help solve the issue, as you can possibly check if you received a bounce for that email shortly after the user attempts to register, and then notify them on the screen?