Mailgun

What Mailgun is

Mailgun is a transactional email and deliverability website at mailgun.com for sending, receiving, tracking, testing, validating, and optimizing email. Its official homepage describes it as a transactional email delivery service and API for developers, with tools for email sending, optimization, validation, inspection, documentation, status, and support.

API and SMTP sending

Mailgun exposes both a RESTful Email API and SMTP relay, so application teams can choose how to send messages from their systems. The API path gives developers structured control over messages, events, templates, and integrations, while SMTP can fit older applications and tools that already know how to send through a mail server.

Deliverability and optimization

Mailgun is not only about accepting messages. The official site highlights deliverability services, reputation tools, blocklist monitoring, inbox placement, authentication protocols, suppression management, analytics, and expert support. These features matter because email outcomes depend on sender identity, reputation, recipient engagement, and mailbox-provider rules.

Validation and inspection tools

Mailgun also offers validation and inspection products. Validation can check email addresses before a team sends to them, helping reduce bounces and wasted sends. Inspection tools, including capabilities associated with Email on Acid, help preview messages, test rendering, and catch accessibility or layout problems before campaigns go out.

Sinch Email context

Mailgun appears within a wider Sinch Email family that also includes Mailjet and Email on Acid. That context explains why the site links between sending, campaign, deliverability, and email-testing tools. For buyers, Mailgun may be one part of a larger email stack rather than the only product used for every campaign or customer message.

Who uses Mailgun

Mailgun is aimed at developers, SaaS companies, marketplaces, ecommerce businesses, fintech teams, healthcare organizations, martech platforms, publishers, startups, and high-volume senders. It is especially useful when email is generated by software, needs event-level tracking, or requires careful delivery work instead of a simple newsletter-only tool.

Pricing and plan shape

Mailgun's pricing page separates free, Basic, Foundation, Scale, and Enterprise options for Mailgun Send. Plan details can include monthly email volume, daily sending limits, custom sending domains, log retention, message retention, inbound routes, templates, webhooks, validations, dedicated IPs, SAML SSO, support level, and deliverability services.

Why it matters

Mailgun matters because many websites and applications depend on email for account signups, password resets, receipts, security notices, workflow alerts, and lifecycle messages. Outsourcing that infrastructure lets teams focus on product behavior while still paying attention to authentication, delivery events, compliance, and sender reputation.

Limits and cautions

Mailgun does not remove the hard parts of responsible email. Teams still need user consent, accurate sender authentication, bounce and suppression handling, privacy review, abuse monitoring, sensible retry logic, accessible message design, clear unsubscribe flows where required, and a plan for reputation problems or mailbox-provider policy changes.

WHOIS domain data

Data pulled: May 20, 2026 · View current WHOIS record

Domain

mailgun.com

IP address

141.193.213.10

Registrar

NameCheap, Inc.

WHOIS server

whois.namecheap.com

Referral URL

http://www.namecheap.com

Created

December 20, 2003

Updated

November 15, 2024

Expires

December 20, 2033

Nameservers

ns-907.awsdns-49.net (205.251.195.139); ns-1728.awsdns-24.co.uk (205.251.198.192); ns-445.awsdns-55.com (205.251.193.189); ns-1471.awsdns-55.org (205.251.197.191)

Domain status

clientTransferProhibited

DNSSEC

unsigned

Contact privacy

Registrant, admin, and technical contact details are redacted by Privacy service provided by Withheld for Privacy ehf.