We are trying to integrate our app with marketing opt-in options. These options have to then update our Hubspot mailing list.
We have found how we can easily make people opt-out of things, however, we are finding it difficult to understand if we can update hubspot with new contacts via the API.
Also, if someone opts-out, and then updates their preferences so they want to opt-in again, is this possible and how?
Confusion arising from statement below in documentation:
"Note: It is only possible to opt email addresses OUT of all emails or a specific email subscription type, and there is NO UNDO for this operation"