Domain Register Emailer

Everytime we register any domain, we get few companies who email us to make a website for that domain, which leads us to believe there is a way to have a cron/timer job that can capture this data so we can send auto replies we want to save all domains in our database and all the emails and firstname/last name linked to the domain, and we need to the "register date" so that we can email people who have registered their domain in the last 30 days the cron/timer job needs to be coded to fetch new domains registered, and then email those domain owners and log on our side that we have emailed them already so that it doesnt email again.