The main issue is that a customer THINKS they are resubscribing by filling out a subscrption form. Because of this perception there needs to be a way for a customer to re-fill out a subscription form hence opting themselves back in.
Here’s some options I would be happy with:
1. I would even be happy with a special Hubspot page that says “I would like to resubscribe”. Customer puts in email, checks all the right boxes, and then Hubspot interprets this special form differently than all the other ‘regular old forms’. Because of the wording on this special form it would be CLEAR to the customer that they are opting back.
2. Hubspot can trap the submission of the form and sent the customer an email that says “Hey looks like you tried to opt-back in, but because you opted out, I need you to click this link to do re-opt back in”