> For the complete documentation index, see [llms.txt](https://docs.yaycommerce.com/yaysmtp/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yaycommerce.com/yaysmtp/troubleshooting/brevo.md).
# Brevo
### Unrecognized IP address
When sending emails through **YaySMTP** using **Brevo (SMTP)**, you may encounter a failed email log with the following error:
```
[401]: We have detected you are using an unrecognised IP address.
If you performed this action make sure to add the new IP address.
```
#### Error overview
This happens when Brevo blocks the SMTP request because the server’s IP address has not been authorized in your Brevo security settings.
The error will appear in **YaySMTP → Email Logs** when viewing a failed email.
Typical indicators:
* Email status: Failed
* Mailer: Brevo
* Error code: 401
* Message mentions “unrecognised IP address”
#### How to fix it
**1️⃣ Identify the IP address**
Go to: **WordPress → YaySMTP → Email Logs**
Open the failed email and locate the IP address mentioned in the error message.
**2️⃣ Add or authorize the IP address**
1. Log in to your Brevo Dashboard
2. Find the **Authorized IPs** section or click this link:
3. Click **Add a new IP address**
4. Paste the IP address you copied from the YaySMTP error log
5. Save the changes
**3️⃣ Check unauthorized IPs (optional)**
Sometimes an IP address may appear in **both lists** in Brevo.
If the IP exists in the **Unauthorized IP addresses** list, Brevo will still treat it as **unauthorized**, even if it also appears in the Authorized list.
In that case, email sending will still fail.
Here, make sure the IP address:
* ✅ Appears in the "Authorized IP addresses" tab
* ❌ Does NOT appear in the "Unauthorized IP addresses" tab
**4️⃣ Test email again**
Return to your WordPress dashboard > YaySMTP, and send a test email to verify that the issue has been resolved.
