Hi @RBonasoro0 and thanks for the tag @chighsmith ,
In your example, is the manufacturer’s rep a contact, or are we talking about an email address on a custom object?
In HubSpot, emails can only be sent to contacts. So ideally, your manufacturer’s rep would be a contact. (You could use a type field to differentiate between manufacturer contacts and potential customers.)
If your manufacturer’s rep is a contact associated to the deal with a label, such as “Manufacturer,” you should be able to send this easily with HubSpot workflows.
Hope this helps!
Trevor