Mailgun

Mailgun gives you a RESTful API to send and receive emails at scale. You can manage everything from a simple curl command or one of the official client libraries for Python, Ruby, PHP, Node.js, Java, Go, and .NET. It handles SMTP relay too, so you can point any existing mail infrastructure at its servers. The service includes real-time analytics on deliveries, opens, clicks, unsubscribes, and bounces. You can validate email addresses before sending to keep your sender reputation clean. Mailgun also supports email parsing to turn inbound messages into webhooks. There are flexible routing rules for incoming mail, spam filtering, and DKIM/SPF authentication baked in. Logs are searchable and kept for a set period depending on your plan. The free tier gives you 5,000 emails per month for three months, then you move to a pay-as-you-go plan starting at 35 dollars per month for 50,000 emails. Mailgun was founded in 2010 and acquired by Rackspace in 2012, then spun out as an independent company under Thoma Bravo in 2019. It's a good fit for SaaS apps, ecommerce platforms, and any developer who wants reliable email delivery without running their own mail servers.