There is an out-of-the-box soltuion for contacts to opt in/ out of subscriptions by clicking a link in an email. In the same way, just sending an email, we like a selfservice for our contacts to maintain properties/ information stored in Hubspot (ie. name, email, phone etc.). Where thinking of a form where we can decide what proprerties to show and the fields are prefilled with existing information when contact click the link in the email.
