Mailgun email authentication

Developer-focused transactional email API.

SPF record

Add Mailgun to your domain's SPF record with this include:

include:mailgun.org

A complete record for a domain sending only through Mailgun:

v=spf1 include:mailgun.org ~all

What it costs you

5 of your 10 DNS lookups. The include: itself costs one, and Mailgun's record chains to 4 more. Behind it are 30 IP ranges.

At 5 lookups this is an expensive include. If your record is near the limit, this is one of the first places to look — see too many DNS lookups.

Live record

This is what mailgun.org published when this page was generated:

v=spf1 include:_spf.mailgun.org include:_spf.eu.mailgun.org -all

Domains using Mailgun

Found while resolving 293 well-known domains on 2026-08-04 — each authorises mailgun.org in its published SPF record:

DKIM

Enable DKIM inside Mailgun and publish the selector record it generates. DKIM matters more than SPF for deliverability, because a DKIM signature survives forwarding while SPF does not — see how selectors work.

DMARC

Neither SPF nor DKIM protects the address your recipients actually see until DMARC ties them to it. Once Mailgun is authenticating, publish a DMARC record — start at p=none with a reporting address and tighten from there.

Generate a DMARC record →

Check it worked

DNS changes take minutes to hours to propagate. Once published, run the domain through the checker — it resolves the full include chain and reports the real lookup count.

Official documentation

Mailgun setup docs →