So recently I have been getting a decent amount of people spam registering on the site as humans, not bots. This would not be a problem for me in general.
However, because these people are spam registering and my site requires an email verification, these verification emails are usually hard bounced - which affects my SMTP.
This is why I was wondering if it would be possible to not send the email at all if the email is not a valid email. I was wondering if there is some sort of check that can be done to ensure that the email being inputted is actually a valid email or not. Thank you for your help!
All email (and login/registrations) is 100% handled by Wordpress and not wpForo. woForo provides a kind of "form" for ease.
So you must solve this issue via a WP plugin.
Still bounce emails have nothing to do with bothering smtp. It is normal to bounce.
Sorry but i'm not into programming, so maybe someone can help with code.
But i can tell you that we send more that a thousand invalid outgoing emails that bounce back per week (not from Wordpress site but from an other script), and our hosting provider (that handles smtp) haven't complained in years.
I highly doubt reputation of a mail server has something to do with bounce back. Still, maybe i could be wrong.