The method of collecting email addresses is called an autoresponder. That is, a database that stores names and email addresses and can send out pre-programmed email addresses to recipients. These can be customised and sent instantly, 1 day, 5 days and anywhere up to 10 years after the initial email was collected. Very powerful and effective. Third party autoresponders that sit on a separate server are the most effective and you can generate your own signup form to place on your website. Check out the case study here