I have multiple sites that I'm receiving access requests for by not sure why. I'm curious, if there is no email specified in the Access Requests Settings, who gets those by default? Would it be all of the Site Collection admins, all of the Site Owners or the Primary Administrator (As defined at the Tenant level)?
It retrieves the Site Owner's email address via
SPWeb.Site.Owner.Email if the access request email field is not filled in (or is the default value of 'email@example.com').