I am trying to import old emails (both received and sent) into HubSpot using the API. I can create a contact, and add an email engagement to the contact, but the email is never showing up in the user interface. The only thing I see is a The lifecycle stage for was changed to “subscriber” entry in the activity timeline. What I would like to see is the same thing as when you forward an email to @forward.hubspot.com: the full email visible in the user interface. Is that possible?