We want the ability to set an SMTP provider that is only for system emails. A great example is "resend" which is specifically for sending account emails, resets, etc with extremely high deliverability rates. This means that the "default" that we set for the agency for clients to use would not be what sends out password emails in case that gets burned. We would instead set a distinct/additional SMTP provider that we assign to those critical emails and customers would never see in their subaccount.