Hi @Josh ,
Thanks for the answer!
How is the same possible with multiple accounts that are related to multiple email-addresses?
I manage my customer relations from my hubspot account with my business email-address as the base for login. My Customer requires that I’m a user in their hubspot account with an email-address that they provided me with (policy/compliance).
I think that’s quite a usual use-case.
As other SaaS providers solved it long ago, I hope HubSpot will solve this in no-time 
Have a nice day,
Géza