Email server settings
Brevo SMTP settings
The Brevo SMTP settings are smtp-relay.brevo.com on port 587 (or 2525), or on port 465 with SSL/TLS. The user name is the SMTP login shown in your SMTP & API settings, and the password is an SMTP key, not an API key and not your account password.
Last checked October 10, 2026, against Brevo’s own documentation.
Brevo SMTP relay server and ports
| Server, port and securityServer | Port and security |
|---|---|
| SMTP · outgoingsmtp-relay | 587STARTTLS |
| SMTP · outgoingsmtp-relay | 2525STARTTLS |
| SMTP · outgoingsmtp-relay | 465SSL/TLS |
Sign-in: SMTP login + SMTP key
User name: the SMTP login from Settings → SMTP & API: your Brevo account email or a generated [ID]@smtp-brevo.com address. Password: an SMTP key.
Brevo SMTP settings explained
From Brevo’s help article Send transactional emails using Brevo SMTP and its port guide:
- Server:
smtp-relay.brevo.com. - Port 587: Brevo recommends starting with it as the default, and its port guide names 587 for TLS connections. The setup article says to leave the app’s encryption field empty unless you use port 465.
- Port 2525: the alternative when 587 is blocked. Brevo notes that it “is not an officially recognized SMTP port by IETF or IANA”, but most ISPs and cloud hosts support it.
- Port 465: for SSL; select SSL or TLS in the app.
- Brevo’s troubleshooting page sums it up: “Brevo SMTP supports ports 587, 465, and 2525.”
SMTP login and SMTP key
The SMTP relay uses its own login, separate from your account sign-in (Brevo):
- SMTP login: either your Brevo account email or “an automatically generated address in the format
[ID]@smtp-brevo.com”. Changing your account’s login email doesn’t change the SMTP login. - Password: an SMTP key from the SMTP page of your settings (SMTP & API). Copy an existing key or generate a new one if you didn’t save it. Brevo: “Make sure you are using an SMTP key and not an API key.”
Before you send: domain, senders and Postfix
- Add and authenticate your domain. Brevo lists this as the first step and links to its DKIM setup; background: DKIM record.
- Create and configure your transactional senders.
- Enter the settings in your app or plugin: host, port, SMTP login and SMTP key.
For a Postfix server, Brevo’s developer guide relays through port 587:
# /etc/postfix/main.cf
relayhost = [smtp-relay.brevo.com]:587
# /etc/postfix/sasl_passwd
[smtp-relay.brevo.com]:587 USERNAME:master_password
Replace USERNAME with your SMTP login and master_password with your SMTP key. If the relay doesn’t accept IPv6 connections, Brevo suggests setting inet_protocols to IPv4 in main.cf.
Common Brevo SMTP errors
| Error or symptom | Fix |
|---|---|
535 5.7.8 Authentication failed | Use the login from SMTP & API settings (not the relay host name) and an SMTP key, without stray spaces or line breaks, and match the encryption to the port. Generate a new key if you didn’t save the old one. |
525 5.7.1 Unauthorized IP address | Blocking of unknown IPs is on. Add the sending IP address to your authorized IPs. In containers or cloud setups, check the real outbound IP first; it can be a NAT gateway. |
450 Your SMTP account is not yet activated | Transactional sending needs a separate activation. Request it by opening a support ticket from your Brevo account. |
| Connection opens, but no server banner arrives | A firewall or the cloud provider blocks outbound SMTP. Ask the host to lift the restriction, or switch to port 2525. |
| Messages queued but not sent | Your credits are used up. Check the Email queue under Transactional → Real time → Usage and plan, then buy credits or upgrade. |
| “Blocked” events in the transactional logs | Brevo blocks contacts after spam reports, unsubscribes, hard bounces or a manual block. Review the blocked contacts. |
Error texts and fixes from Brevo’s Troubleshooting – Issues with Brevo SMTP. For codes from the recipient’s server, see the SMTP error codes reference.
What the Brevo SMTP relay is for
Brevo’s developer docs describe the SMTP relay as “designed for transactional emails”. It doesn’t support batch sending; for that, Brevo points to the batch sending endpoints of its API.
Brevo blocks contacts after hard bounces, so a mistyped address at sign-up ends up on the blocked list. Check addresses when they’re entered with an email validation API, or clean an imported list with the bulk email verifier first.
Sources
Checked on October 10, 2026. Server names, ports and sign-in rules come from these official pages:
Other SMTP relay services
Brevo SMTP settings: FAQ
What are the Brevo SMTP settings?
smtp-relay.brevo.com, port 587 (or 2525) with the app’s encryption field left empty, or port 465 with SSL/TLS. User name: your SMTP login; password: an SMTP key.What is my Brevo SMTP username?
[ID]@smtp-brevo.com address.Can I use a Brevo API key as the SMTP password?
Which port should I use for Brevo SMTP?
Why does Brevo say “Unauthorized IP address”?
525 5.7.1 error means blocking of unknown IPs is on and the IP your server sends from isn’t on your list of authorized IPs. Add the actual outbound IP in Brevo.Email validation API
Validate recipients before you send through Brevo
emailvalidation.io checks syntax, MX records and the mailbox over SMTP, flags disposable, role and free addresses and returns a quality score, in one request.
/v1/info Email validation API Read the documentation
100 free validations every month. No credit card required.
GET https://api.emailvalidation.io/v1/info?
{
"email": "support@emailvalidation.io",
"user": "support",
"tag": "",
"domain": "emailvalidation.io",
"format_valid": true,
"mx_found": true,
"smtp_check": true,
"catch_all": null,
"role": true,
"disposable": false,
"free": false,
"score": 0.64,
"state": "deliverable",
"reason": "valid_mailbox",
"did_you_mean": ""
}