Two transactional email providers, compared on price, features and ratings, so you can pick fast.
Updated November 2026
THE VERDICT
Mailgun wins on flexibility and compliance. Postmark wins on speed and simplicity.
Both are developer-grade transactional ESPs starting at $15/mo. Mailgun is the more flexible infrastructure play, usage-based pricing, EU data residency, ISO 27001, and a HIPAA BAA, built to scale and handle regulated sends. Postmark is the deliverability-and-speed specialist, with 45-day log history and a strong support reputation, but it's US-only, won't sign a BAA, and skips marketing features.
Winner cells are tinted, green where Mailgun leads, violet where Postmark does.
FAQ
Postmark is specifically known for fast transactional delivery and a clean sending reputation; Mailgun offers more deliverability tooling and controls at scale.
Mailgun will sign a BAA, making it HIPAA-capable. Postmark explicitly will not sign a BAA, so it's not an option for PHI.
Postmark is transactional-focused (with basic broadcast streams). For full marketing campaigns you'd pair Mailgun with its marketing tools or use a dedicated platform.
Why not both?
Use both behind one API.
Route Mailgun, Postmark, or both, and switch providers without changing your code. Courier sits in front of every channel.
Pricing, plans and feature availability as of November 2026 and may change. Ratings are aggregated from public review platforms. Mailgun is a Sinch product; Postmark is an ActiveCampaign product.