Tools / Mailgun / Mailgun vs Postmark
Email APIs for sending, receiving, and parsing.
Mailgun is a transactional email API service for developers, part of Sinch (the site's logo pairs the two brands). The homepage is organized around four product areas: Send (an email API for sending, with inbound message parsing and connections to CRMs or other data tools), Optimize (a deliverability suite the site describes as combining applications and expertise), Validate (a real-time email validation API plus drag-and-drop list cleaning to remove invalid and high-risk addresses), and Inspect (email preview and quality-assurance tools built on Email On Acid technology, including accessibility checks). The site says Mailgun scales from thousands to millions of emails and cites customer results including 21% fewer bounces, 65% higher open rates, and 100% more clicks. It also references a Forrester study modeling potential improvements for a composite customer, and carries a testimonial from Michael Sacca, VP of Product at Dribbble, on deliverability at volume.
Transactional email that lands in the inbox, fast.
Postmark is a transactional email delivery service that sends application email — password resets, receipts, notifications — through a REST API or SMTP. The site says it has been delivering email since 2010 and has sent billions of messages for companies of all sizes. Sending works through an API with official libraries for Node.js, Python, Ruby on Rails, Ruby, PHP, and C#, plus a plain curl example for testing. API requests include a MessageStream field (the sample uses "outbound"), which separates types of outbound email. Developer documentation lives at postmarkapp.com/developer, and you can sign up for a free trial from the homepage. The homepage names IKEA, 1Password, Asana, Webflow, Minecraft, UNICEF, Paddle, Indie Hackers, Litmus, and Moz among its customers. Several customer quotes on the page describe migrating to Postmark from SendGrid or Mailgun, citing deliverability and speed of delivery.