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Mailgun

Mailgun is a YC Winter 2011 (W11) company. Based in San Francisco, CA, USA. Team of 51.

  • API
  • Email

About Mailgun

GPAgent's own fund-neutral profile, written from public information. Updated Oct 5, 2026.

Summary

Mailgun builds an email API platform for developers and engineering teams at companies that send transactional and marketing email at scale. It handles sending, receiving, tracking, validation, and inbox testing, replacing custom-built email infrastructure and direct SMTP configuration. Teams at product companies use it to ship reliable email delivery without managing the underlying systems themselves.

Business model

A free tier plus paid plans scaled by volume and features, with an enterprise tier for high-volume senders.

Go-to-market

Developers adopt Mailgun self-serve through an API and free tier, with a direct sales path for enterprise accounts requiring high-volume throughput.

From the Y Combinator listing

How Mailgun describes itself in Y Combinator's public directory. Original listing (opens in a new tab)

Email API service.

Mailgun is a developer-focused email delivery platform that empowers companies to send, receive, and track transactional and marketing emails through an API. Founded in 2010, Mailgun became a Y-Combinator success story later acquired by Rackspace. In February 2017, Mailgun spun back out as a standalone business focused on building best-in-class email deliverability solutions. We are headquartered in San Antonio with remote teams in San Francisco and Austin. Customers like Slack, Lyft, Github, and Reddit rely on Mailgun to deliver email to their customers.

Facts

Industry
B2B / B2B -> Engineering, Product and Design
Location
San Francisco, CA, USA
Team size
51
Status
Acquired
Stage
Early

Founders (2)

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