So recently I have been dealing with an issue with people entering invalid emails when registering. This leads to my emails getting hard bounced, which leads sendinblue to decrease my SMTP quota. 

I found a really nice API that I can use provided by https://verifalia.com/. This API will allow me to check the email before I send that email a verification link in order to make sure that the email actually exists.

Right now in wpforo if you want you could register with a bogus email that does not actually exist, and this hurts my website as it leads to hard bounces all the time.

<?php if( email_exists( $email ) ): ?>
    <div class="wpf-tr">
        <div class="wpf-td wpfw-1">
            <i class="fas fa-info-circle wpfcl-5 wpf-reg-info" aria-hidden="true" style="font-size:16px;"></i> &nbsp;<?php wpforo_phrase('After registration you will receive an email confirmation with a link to set a new password') ?>
        </div>
        <div class="wpf-cl"></div>
    </div>
<?php endif; ?>

Here is the code segment I found that is in charge of the email verification when registering. I was wondering how I could tie in the verifalia API into this so that my site can actually check if an email exists before sending the verification link.

Thanks for your help,

Tumph