I installed and tested this addon but it is only blocking the users trying to use googlemail.com/gmail.com variant. It is not blocking registrations when users are using "." in the email address.

Quite unfortunate.

Unlike back when this Mod was made, today it's really useless to even bother requiring a valid email. Because the autospam programs have defeated pretty much all human verification on the most popular email services. And they get the verification code anyway, directly from your site on pageload after they "click" the submission.. (XRumer)

If you want to stop autospam I would recommend one of the registration time check mods. They're very effective.

I don't even use the email verification anymore, haven't for a little over a year. It's simply obsolete, now.

This mod has two author's mistakes...

First: Search
Replace it with

Second: authors mistake - is metodological.... If we have email 'test.1test@gmail.com' in our user database, and we register new email 'test.1.test@gmail.com' - we have successfull registration...

Why?
Because author search (in user database) email 'test1test@gmail.com' (without dots)