While troubleshooting various notification issues, it may be helpful to capture a list of all the work items that are currently sending notifications to a given email address.
select wi.name, wi.description, wi.type, wi.type, wi.state, ident.display_name, ident.email from spt_identity ident, spt_work_item wi where wi.owner=ident.id and ident.email='ashley.simpson@demoexample.com';
In this example, the Identity for Aaron Nichols was accidentally given the email address, "Ashley.Simpson@demoexample.com". This would cause Aaron Nichols to never receive any notifications for work items assigned to him, while Ashley Simpson's email box would be flooded with notifications even though no work items appeared in her IdentityIQ Inbox.