Mailgun SMTP settings: smtp.mailgun.org (smtp.eu.mailgun.org), port 587
Mailgun SMTP relay: host smtp.mailgun.org (EU: smtp.eu.mailgun.org), ports 587/2525 STARTTLS or 465 SSL, SMTP username postmaster@yourdomain with a domain SMTP password. Free trial limits and error fixes.
Mailgun outgoing mail server:
smtp.mailgun.org, port <code>587</code> (STARTTLS) or <code>2525</code> (STARTTLS) or <code>465</code> (SSL/TLS) or <code>25</code> (STARTTLS), username = postmaster@yourdomain.com (default SMTP user) or an SMTP credential you create for the domain, password = the SMTP password shown in Sending → Domain settings → SMTP credentials.
Mailgun SMTP settings at a glance
| Outgoing (SMTP) host | smtp.mailgun.org (US region) — smtp.eu.mailgun.org (EU region) |
|---|---|
| Ports & encryption |
587 — STARTTLS <em>(recommended)</em>2525 — STARTTLS465 — SSL/TLS25 — STARTTLS |
| Username | postmaster@yourdomain.com (default SMTP user) or an SMTP credential you create for the domain |
| Password | the SMTP password shown in Sending → Domain settings → SMTP credentials (not your account password) |
| Authentication | Each sending domain has its own SMTP credentials; the region of the host must match where the domain was created. |
How to set up Mailgun SMTP
- Sending → Domains → Add new domain → add the DNS records → verify.
- Domain settings → SMTP credentials → reset/create the postmaster password.
- App settings: host smtp.mailgun.org (or EU), port 587, STARTTLS, username postmaster@yourdomain.com, password = SMTP password.
Sending limits
- Free trial: 100 emails per day for 30 days (then Foundation from around $35/month); sandbox domains only send to authorised recipients.
- Domain must be verified with SPF/DKIM TXT records.
Things that catch people out
- Using the US host for an EU domain fails authentication.
Common Mailgun SMTP errors
| Server reply | Meaning | Fix |
|---|---|---|
535 5.7.0 Mailgun is not loving your login or password | Wrong SMTP password or wrong region host. | Reset the domain's SMTP password; check region. |
550 5.7.1 Relaying denied / Sandbox domain | Sandbox recipient not authorised. | Add a verified domain. |
More codes: 535 authentication failed, 550 relay denied, 554 rejected as spam, connection timed out — or all SMTP error codes.
When Mailgun is not enough for your app
When a provider caps you or blocks a port, point the same app at QueenSMTP instead: host smtp.queensmtp.com, port 587 (STARTTLS) or 465 (SSL), your SMTP username and password from the dashboard. $5/year plus $0.10 per 1,000 emails, 100 free a day to test.
Get SMTP credentials — free to test Test Mailgun nowRelated settings
Mailgun SMTP — questions
smtp.mailgun.org for US-region domains and smtp.eu.mailgun.org for EU, on port 587 (STARTTLS) or 465 (SSL), with postmaster@yourdomain and the domain SMTP password.
Related Guides
Continue learning with these related articles