Hi @deforgej
At present, HubSpot always, automatically deduplicates contacts based on email address.
Each unique email address can only be associated with one contact. Contacts can not share email addresses. And, while you could import the shared email address into a custom, non-standard, contact property, that property could not be used for the sending of emails.
I’ve seen this be an issue before, in markets where businesses deal with contacts who share addresses. Unfortunately, HubSpot might not be the right solution for you in this instance. Although I’m not sure which systems actually allow the sending of emails multiple times to the same address and/or with differing personalisation.
Good luck.