Mailgun vs. Courier

150,000+ companies. 400 billion emails a year. 99.99% uptime — backed by SLA Mailgun is the full-stack email infrastructure platform developers and marketers trust to send, test, validate, and improve deliverability at scale. One platform covers the entire email lifecycle: preview and fix rendering issues before you send, clean your lists in real time, fire emails via API at any volume, and surface deliverability problems with AI before they cost you. SOC 2 Type I & II, HIPAA, GDPR, ISO 27001 certified. Trusted by Microsoft, Lyft, and American Express.

Courier is notification infrastructure for customer messaging, built for humans and AI agents. It sits between your app and every channel you send on: email, SMS, push, in-app inbox, chat, and webhooks. You send one request, and Courier works out where it goes, what it looks like, and whether the user wanted it at all. Teams use it for the messages a product has to send: onboarding, alerts, receipts, reminders, and account notices. You keep the providers you already pay for. Courier is the layer above them.