SendGrid, an email company that sends transactional email communications on behalf of customers including Foursquare, Pinterest, Airbnb, Twilio, Spotify, and Pandora, has launched a new email marketing platform for businesses. The new platform will compete with the likes of MailChimp and Constant Contact, providing customers with a platform to create, send and track email marketing messages. The service is priced by the volume of emails sent, rather than by the number of subscribers a company has.