Easy way to disable newsletter subscription Email from going out in Magento 1.9?

Magento 1.9.4
Porto theme

I googled and googled and I can’t believe I can’t find an easy way to do this. This is what’s happening:

Some bad person is feeding thousands and thousands of Email addresses into our Newsletter Subscription box. Then Emails go out which say:

logo and “You have been successfully subscribed to the newsletter.
Thank you, companyNAME”

Then, when the people receive this Email, they either report it as SPAM or Google’s and Yahoo’s incoming mail filter won’t even let it through and mark us as spammers right away which results in our inability to deliver genuine Order Confirmation Emails to customers.

We would like to keep the option for people to sign up for the Newsletter there but we really need to turn off that Email (allow customers to sign up for the newsletter but NO Email to be sent).

I checked here:

System - Configuration - Customers - Newsletter –> but there is no option NOT to send the Email out – just pick your templates etc.

Simple solutions would be preferred – the only ones I found on the Internet so far were like editing and creating 10 files etc. and that seems unnecessarily complicated for such a simple ask.