workflow – Send email to users with expired documents

I want to be able to send email to each user which has expired documents and be able to know when the expiry date email was sent. The item contains worker name, their expiry date, and the heading of ‘Expiry Date Send Date’ which is empty right now and few other headings.

I looked around the internet and all I could find was to be able to send email to one address rather then to each of the user with the expiry document.