Create an application to send a templated email to all clients in the database asking them to log in and update their details.
This email contains a link to a website where the client's information is retrieved from the database (removing the client's ID from the querystring
to prevent anyone from trying to access any other account details).
The client can either confirm that their details are correct, update the details or remove the details from the database.
Dates and times of visits and updates are recorded to enable a follow-up request to those who have either not visited the site or visited the site but didn't update their details.