SendGrid, acquired by Twilio, is a cloud-based email infrastructure and delivery service. Provides high email deliverability, scalability and email analytics (email requests, deliveries, bounces, spam reports, clicks, opens, unsubscribes, etc). Offers pay-as-you-go pricing model with full feature set in the free plan, limited by 200 emails per day. Delivers over 14 billion emails per month for 180,000+ clients including Uber, Foursquare, Spotify, Twilio, Airbnb, Pinterest, Path and Hootsuite. Headquartered in Boulder, Colorado, with offices in Denver, CO; Orange County, CA; and Anaheim, CA. Incubated in TechStars in 2009.