Before you do this, you will need to sign up to an email marketing platform. It's impossible to manually send messages to individual email accounts so you need email software. You can ease pass this work through Getresponse or Aweber.
Both email marketing platforms are the best any blogger can use. You can monitor how much traffic to your website comes in through your email list using Google Analytics. This will help you assess the performance of your email marketing campaign. Yoast also offers marketing tools with which you can monitor your blogs email marketing campaign.
We personally recommend Getresponse, as you can build fantastic autoresponder messages which allows you to automate your emails once someone signs up to your list. Getresponse also makes creating landing pages and sign up forms so simple.