Mailjet SMTP settings: in-v3.mailjet.com, port 587
Mailjet SMTP relay: host in-v3.mailjet.com (in.mailjet.com), ports 25/587/2525 STARTTLS or 465 SSL, username = API key, password = secret key. Free plan (6,000/month, 200/day) and setup.
Mailjet outgoing mail server:
in-v3.mailjet.com, port <code>587</code> (STARTTLS) or <code>2525</code> (STARTTLS) or <code>25</code> (STARTTLS) or <code>465</code> (SSL/TLS), username = your Mailjet API Key, password = your Mailjet Secret Key.
Mailjet SMTP settings at a glance
| Outgoing (SMTP) host | in-v3.mailjet.com (alias in.mailjet.com) |
|---|---|
| Ports & encryption |
587 — STARTTLS <em>(recommended)</em>2525 — STARTTLS25 — STARTTLS465 — SSL/TLS |
| Username | your Mailjet API Key |
| Password | your Mailjet Secret Key |
| Authentication | Account Settings → API Key Management (Primary and Sub-account) shows both keys; SMTP uses them as username/password. |
How to set up Mailjet SMTP
- Account → Sender addresses & domains → add and validate.
- Account → API Key Management → copy API key and secret.
- App settings: host in-v3.mailjet.com, port 587, STARTTLS, username = API key, password = secret key.
Sending limits
- Free plan: 6,000 emails per month with a 200-per-day cap and Mailjet branding; Essential from about $17/month.
- Sender address/domain validation with SPF and DKIM required.
Things that catch people out
- Sub-account keys only send for that sub-account's validated senders.
Common Mailjet SMTP errors
| Server reply | Meaning | Fix |
|---|---|---|
535 5.7.8 Authentication failed | Wrong key pair. | Copy both keys from API Key Management. |
550 5.1.7 Sender not validated | From not validated. | Validate the sender. |
More codes: 535 authentication failed, 550 relay denied, 554 rejected as spam, connection timed out — or all SMTP error codes.
When Mailjet 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 Mailjet nowRelated settings
Mailjet SMTP — questions
in-v3.mailjet.com on port 587 (STARTTLS) or 465 (SSL), with your API key as username and secret key as password. The free plan allows 6,000 emails a month, 200 a day.
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