I need to prevent email sending from the mass_mailing module. In res.partner I added a field "email_notifications" and unless this is True no email from the mass_mailing module should be sent.

I'm looking at the mass_mailing module and I don't see any relation or partner_id on which I could write a control to check the status of "email_notifications". The only thing that I found is that it searches for email and name in res.partner in the module "mail.mass_mailing_contact" and more users can have the same email.

So any suggestions how to prevent the mass_mailing to sent email to those that have "email_notifications" set to false in res.partner model?

I need to do this because of GDPR.