Email is still the most direct way to get your message out, you can organise email campaigns using services such as Mailchimp. You can also automatically sghare your blog content to email subscribers.
Almost every internet user has an email address, getting people to sign up to recieve email from you is the challenge.
Don't email too much, give value to your subscribers and make sure your emails look professional. Use email templates that are responsive so they look good on mobile phones.
Customer email addresses are a valuable resource, collecting them is a challenge and it is very easy for customers to unsubscribe if you do it wrong.