# Mailjet

Source: https://catalystgroup.gg/docs/email-delivery/mailer-mailjet/
Updated: 2026-10-19 · By Duane Garner

Connect CRM-NG SMTP to Mailjet with your API key and secret key, and validate the address or domain you send from.

This guide shows you how to send your WordPress email through Mailjet, an email service for both transactional and marketing mail. It suits small businesses that want one place for website mail and newsletters. Mailjet has a free plan with a daily limit and no card required; check its site for the current allowance.

 

The **Mailjet** mailer sends through Mailjet's API. Mailjet uses a pair of credentials, an **API Key** and a **Secret Key**, and both are needed. You also validate the sender address or domain.

 

## Before you start

 
- A Mailjet account (sign up at `https://www.mailjet.com/`). New accounts may be reviewed before sending in volume.
- A domain you control, with access to its DNS records.
- Administrator access to your WordPress site.

 

## Step 1: Add and validate your sender

 
1. Sign in to Mailjet
  Go to `https://app.mailjet.com/` and sign in.
2. Open Senders & Domains
  Open **Account settings** (from your name in the top corner) and choose **Senders & Domains** (look for **Add a sender domain or address**).
3. Add your domain
  Add the domain you send from. Mailjet asks you to prove ownership, usually with a TXT record or a file on your website.
4. Authenticate the domain
  On the same page, open the domain's SPF and DKIM settings and add the records Mailjet shows at your DNS provider. Return and run the check until both show as valid.
5. Add a sender address
  If you only want to validate one address, add it as a sender and click the link in Mailjet's confirmation email.

 

See [Adding DNS records](https://catalystgroup.gg/docs/email-delivery/dns-records/) for help.

 

## Step 2: Get your API key and secret key

 
1. Open API key management
  In **Account settings**, choose **API Key Management** under the REST API section (the plugin's link goes to `https://app.mailjet.com/account/apikeys`).
2. Copy the API key
  Copy the **API Key** of your primary key, or create a sub-account key for this site.
3. Copy the secret key
  Reveal and copy the **Secret Key** for the same key. If you cannot see it, generate a new one; note that this breaks anything else using the old secret.

 

## Step 3: Connect in CRM-NG SMTP

 
1. Choose the mailer
  In WordPress, open **CRM-NG SMTP → Settings → General** and set **Mailer** to **Mailjet**.
2. Paste the API key
  Paste the API key into **API Key**.
3. Paste the secret key
  Paste the secret into **Secret Key**. The two must come from the same key pair.
4. Set the sender
  Set **From Email** to your validated address or an address on your validated domain, and set **From Name**. Tick **Force From Email** if other plugins change the sender.
5. Save
  Press **Save Settings**.

 

## Send a test email

 

Open **CRM-NG SMTP → Tools → Email Test**, enter your address in **Send To**, and press **Send Email**. In Mailjet, the statistics or message history page shows the result. See [Sending a test email](https://catalystgroup.gg/docs/email-delivery/send-a-test-email/).

 

The domain check on the test page looks for `spf.mailjet.com` in your SPF record.

 

## Troubleshooting

 
- The API key and secret key do not match, or one is wrong: [401 Unauthorized or Forbidden](https://catalystgroup.gg/docs/email-delivery/error-401-unauthorized-or-forbidden/) and [Invalid API key](https://catalystgroup.gg/docs/email-delivery/error-invalid-api-key/)
- The From address is not validated: [553 Sender address rejected](https://catalystgroup.gg/docs/email-delivery/error-553-sender-address-rejected/)
- Mailjet suspended or is reviewing the account: [Account blocked](https://catalystgroup.gg/docs/email-delivery/error-account-blocked/)
- You have reached your daily or monthly limit: [Email sending limit reached](https://catalystgroup.gg/docs/email-delivery/error-email-sending-limit/)
- The recipient is blocked after earlier bounces: [Email address in suppression list](https://catalystgroup.gg/docs/email-delivery/error-email-in-suppression-list/)
- Mail arrives in spam: [Emails landing in spam](https://catalystgroup.gg/docs/email-delivery/emails-landing-in-spam/)

 

## Related

 
- [Choosing a mail service](https://catalystgroup.gg/docs/email-delivery/choose-a-mailer/)
- [Adding DNS records: SPF, DKIM and DMARC](https://catalystgroup.gg/docs/email-delivery/dns-records/)
- [Verifying your DNS records](https://catalystgroup.gg/docs/email-delivery/verify-dns-records/)
- [Sender name, address and the Force settings](https://catalystgroup.gg/docs/email-delivery/sender-name-and-address/)
- [Securing settings with wp-config constants](https://catalystgroup.gg/docs/email-delivery/secure-settings-constants/)