In a site where new user registrations will need approval, we want the notifications to go to particular people depending on the details entered by the new user.  For example, if the user says they are in the north-west region, we want the notification to go to one email, and north-east to another. In fact the email address(es) will be determined by looking up users in a particular role associated with the same region as the new applicant, and if there aren't any we will fall back on an default account.

I see we can plumb in our own code on the registration event https://www.mojoportal.com/user-registered-event-handlers.aspx Could this be used to send the notification email as described?  Presumably the core mojoPortal code still runs, wanting to send the notification to the email(s) specified in site settings, but perhaps we could leave that blank, or use an unattended email account.

Does this sound plausible? Any advice gratefully received.