There are a few valid reasons why a Contact who has never been sent a HubSpot email might have their Original Source Type = 'Email Marketing'.
- The Contact was forwarded the email from another Contact and clicked on a link in the email to first visit your site.
- The Contact received the email as a member of a distribution list and clicked on a link in the email to first visit your site.
- The Contact was sent the email as a different Contact with a different email address, clicked on a link in the email to visit your site, and submitted a form using a second email address.
- The Contact clicked on a link from a non-HubSpot email that contained email tracking parameters to first visit your site.