I Have problem with connecting to brevo

Questions
1

Hello,
I’m having an issue connecting n8n to Brevo credentials. I have already created and copied a new API key three times, but I still receive an error saying that the connection cannot be established.
I have also tried several suggested solutions, such as changing my IP address and deactivating/reactivating the API key, but none of them worked.
Could you please help me identify the cause of this issue and suggest a solution? I would really appreciate your assistance.
Thank you!

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2

A few things to check here:

  1. API key type — Brevo has two types: the legacy “API Key v2” and the newer API keys. Make sure you’re using the one your n8n version expects. In the credential settings, it should be the one from Brevo → My Account → SMTP & API → API Keys.

  2. “Allowed HTTP Request Domains” — I can see that field in your screenshot. If your n8n instance is running on a custom domain, make sure that domain is added there (or set to “All”). A restriction here would cause the credential test to fail even with a valid key.

  3. Test vs. actual connection — If you’re on n8n Cloud, the outbound IP might differ from what Brevo sees. Try actually running the node (send a test email) rather than just clicking “Test Connection.”

Can you also share what n8n version you’re on and whether this is self-hosted or cloud?

3

i use vps SumoPod for n8n with Version 2.30.8

4

A few things I’d check before digging deeper:

• Make sure you’re using Brevo’s v3 API key, not an SMTP key.

• Copy the API key without any leading/trailing spaces.

• If you’re self-hosting n8n, verify the server can reach api.brevo.com and that no firewall or proxy is blocking outbound requests.

• If possible, test the same API key with a simple GET https://api.brevo.com/v3/account request in Postman or cURL. If that fails too, the issue is likely with the API key or Brevo account rather than n8n.

If you can share the exact error message or a screenshot of the credentials test (with sensitive information hidden), it’ll be much easier to pinpoint the root cause.

If you’d rather troubleshoot it together, feel free to book a free call: https://calendly.com/dansakisamuel2⁠�. Happy to take a look with you.

5

Hi @Filteran_Teradha_Fis Welcome!
A 401 that survives three fresh API keys and doesn’t budge when you change IP points at Brevo’s Authorised IPs security feature, not at the key itself. Brevo blocks API calls from any IP it hasn’t seen before, and on accounts created after mid-2024 it’s on by default. Regenerating the key can’t help because the block is on the IP, and every new IP you switch to is also unrecognised, which is why none of what you tried moved it.
Your VPS’s outbound IP is what Brevo sees, so authorise that one:

  1. In Brevo, top-right organisation name > Settings > Security > Authorised IPs.
  2. Add your SumoPod VPS outbound IPv4. Get it by running curl https://api.ipify.org on the box, or from the SumoPod panel.
  3. Save, wait about 5 minutes, then test the credential again.
    Also check the account owner’s inbox for a Brevo “Validate your IP address” email, clicking the link in it authorises the IP directly.
    https://help.brevo.com/hc/en-us/articles/5740111683858-Authorize-and-block-IP-addresses-for-API-security
6

I also asked a few other people about this issue, and they told me they are experiencing the same problem. They are also unable to connect their Brevo credentials, so it doesn’t seem to be an issue specific to my account.

7

the image clearly shows an “Authorization failed” message, which is a classic “the server heard me, but didn’t like what I said” error.

This means your n8n instance can connect to Brevo’s servers, but the API key you’re providing isn’t being accepted. Given your strong background, especially with “Basic Authentication” and “Secure Connection,” you know this boils down to the credentials themselves.

Let’s dissect this new information:

The New Error Message:

Couldn't connect with these settings. Authorization failed - please check your credentials.

Why this is happening (and how to fix it):

  1. The API Key is Incorrect or Revoked:

    • Double-check the source: Go back to your Brevo account (formerly Sendinblue).
      • Navigate to SMTP & API (or similar, depending on Brevo’s UI changes).
      • Ensure you are copying the correct API key. Brevo typically has different types, sometimes labeled “v2” (legacy) and “v3” (recommended). n8n’s Brevo node expects the “API Key v3”. This is crucial and often the reason for this error.
      • Generate a new v3 API key if you’re unsure or if you’ve been reactivating older ones. Copy it immediately.
    • Paste without extra spaces: When copying and pasting into n8n’s API Key field, ensure there are no leading or trailing spaces. Even a single invisible character can invalidate the key.
    • Active Key: Confirm the key you’re using is active and hasn’t been accidentally revoked or expired.

  2. API Key Permissions (Less Common for Connection Test):

    • While usually a connection test only requires basic access, some heavily restricted API keys might fail.
    • Ensure the API key you generated has full permissions, or at least sufficient permissions to access the Brevo features you intend to use with n8n (e.g., managing contacts, sending emails). Brevo often allows you to set granular permissions when creating keys.

  3. n8n Instance Specifics (Unlikely but worth noting):

    • If you’re running multiple n8n instances or environments, ensure you’re entering the API key into the correct instance’s credentials. (Given your work with “Deployment & Version Control,” you’re likely aware of this, but it’s a common oversight).

Step-by-Step Fix:

  1. Log in to your Brevo account.

  2. Navigate to SMTP & API.

  3. Locate or generate a new API Key v3. This is key. The screenshot itself has a hint below the API key field about Brevo having v2 and newer API keys.

  4. Carefully copy the entire API Key v3 to your clipboard.

  5. Go back to your n8n Brevo credential setup.

  6. Delete the existing (masked) API key in the

    API Key

    field.

  7. Paste the newly copied API Key v3 into the field. Ensure no extra spaces are pasted.

  8. Click “Retry” or “Save” (if available) to test the connection.

This “Authorization failed” error is almost exclusively due to the key itself being incorrect or of the wrong type. Focus on getting that Brevo API Key v3 perfect!

Trying to fix an “Authorization failed” error with the wrong API key is like trying to use a

Switch

node without a valid expression: it’s just not going to route anywhere useful.

8

Thanks for letting us know about this, We have created CV-19 as the internal dev ticket to look into it.

9

Hey! This looks like a classic API key authentication issue. You can try these quick steps to fix it:

  1. Regenerate API Key: Go to your Brevo account dashboard, delete the old API key, and generate a brand new API v3 key to ensure it hasn’t expired or been corrupted.

  2. Check for Extra Spaces: When copying and pasting the API key into n8n, make sure there are no accidental trailing or leading spaces.

  3. Verify Key Version: Ensure you are using the API v3 key, as older versions are deprecated.

Let me know if this helps resolve the authorization error!"

10

Thanks everyone for reply and helping me

11

Did you get it working in the end?