We do not have an email validation function as such, but what you can do is turn off the option to allow a user to use a custom password. By doing this, they would have to access their email to get the password which is generated automatically but sent via email.
To do this you would need to go to Optimizemember >> General Options >> Registration/Profile Fields >> Allow Custom Passwords during Registration? – and set this to NO.
This should have the same effect as no user that provides an incorrect email will be able to gain access.