How to unsubscribe from transactional email

Hi,
I send email to people who did not subscribe to anything. It’s only prospecting email to mainly info@xxxx.com but following e-privacy law, I have to insert an opt-out in these emails. So mainly I don’t have list, I send these email one by one. And I would like that if one unsubscribe, that I need to be sure he doesn’t get another email from me. If I use conversation email (transactional) with the unsubscribe link, it works, but it only blocklist the user from the campaign and not from transactional email. I’m just trying to figure it out how I could achieve this with Brevo.