Mailchimp
The Mailchimp integration allows you to automatically sync the contact information of your ticket purchasers directly to your Mailchimp account.
With a free introductory plan, you get up to 12,000 free emails per month, 2,000 total subscribers, and a variety of template options. MailChimp makes it easy to quickly send out newsletters, announcements, invitations, etc, to all your customers.