From the sidelines, I'd think the answer is that your email platform should have that feature, or you should consider using entirely separate flows/tools for transactional emails and marketing emails. Not a lawyer, but AFAIK transactional emails are not subject to Spam rules & don't even need to have an "Unsubscribe" link. Mixing the two is just causing yourself needless pain.

> From the sidelines, I'd think the answer is that your email platform should have that feature

It does. But the user clicked "No I want to unsubscribe all"

Can you rephrase the choices?

- Unsub from this marketing topic.

- Unsub from all marketing mails. You will continue to receive paid course content; to terminate see [account deletion request page].

On the account deletion page, make it clear that they'll lose out on further paid content, don't come back crying, blah blah.