Setting to turn off Non-Hubspot forms from adding/merging email addresses

We are B2B and contacts log in for multiple devices with different emails/share accounts. If a contact record currently exists and Hubspot picks up that another email was used on the same device, Hubspot will add a secondary email to the existing record. Even if the domains are different.

The big issue we see is it will pull a secondary email in and set it as the primary email, but the new email may have a different domain. Yet, the primary company is still the one associated with the same domain as the original email.

For example, the original record lists john@coke.com as the primary email, then the user fills out a non-Hubspt form and Hubspot pulls in the new email, let’s say john@pepsi.com. But the primary company is still Coke. Yet it has now set john@pepsi.com as the primary email. Hub is then taking our accurate data and making it inaccurate.
Hubspot simply cannot accurately determine if this new email is associated to the contact. Account sharing is very prevelant in the B2B and even B2C world. The idea that any secondary email used on a device autamatically means they are the same contact is ludicrous.

Has there been any update to this? People have been talking about it since 2017. Here is a comment from 2019 that accurately describes the problem:

  • Formerly, we had cookies turned on for our forms. But that meant that if a mailing list subscriber forwarded one of our emails to another person--and that person filled out a form on our site to sign up for the mailing list… then that new person’s email address becomes associated with the original subscriber’s contact record.
    While we wait for a solution, we have had to turn off cookies for all of our forms (so no longer benefiting from any analytics, tracking, form fills, or otherwise) and have to manually sift through 1,000’s of records to remove inaccurately associated secondary addresses--as we cannot create new, unique records for those addresses until they’ve been removed from their currently associated accounts. And while we work on this, the new contacts are not receiving our communications, which is hurting our reach and impact.

https://community.hubspot.com/t5/APIs-Integrations/Is-there-a-way-to-delete-secondary-email-address-via-API/m-p/221562#M458