SendGrid is a cloud-based email service provider (ESP) that helps businesses send marketing and transactional emails. It acts as a third-party SMTP server, handling the complexities of email delivery so users can focus on their content and strategy.

SendGrid provides features like email APIs, marketing campaign tools, and analytics to optimize email deliverability and engagement. SendGrid handles a massive 100+ billion emails a month with 99.99% uptime. It's great if you're sending a lot of emails