Navigate to email settings
From your HubSpot marketing dashboard, navigate to Content > Content Settings. From the left sidebar, select Marketing > Email, then click the Subscriptions tab.
Create email for resubscription
Before you turn this feature on, you'll want to make sure you create and publish the email first. Click on Edit Email.
You'll be taken to a newly created resubscribe email where you can edit whatever parts of the email you'd like for personalization, like the From Name, From Email, Message Subject, etc. This email will have pre-populated text that you can alter to make it your own, but you must keep the blue Update Your Subscription Preferences personalization tag.
And if you've never created an email in HubSpot, check out this article. Once you've edited your email as needed, click Publish.
Once you publish your resubscription email, you'll be taken back to your email settings where you should now see the link reading, Edit Email instead of Create Email. At this point, you can switch the Resubscription email toggle ON and click Save.
Now, when someone whom was previously unsubscribed from your email communication comes back to your site and fills out a form or lead flow, they should see something like this: