Brevo, previously Sendinblue, is a reasonable choice for WordPress transactional email with a generous free tier. Its most common problem is not a setup failure — it is a setup that appears to work while sending mail nobody can verify as yours.
The one-glance test
Send a message through Brevo and look at how it appears in the recipient’s inbox. If you see something like:
Your Shop <[email protected]> via ha.d.sender-sib.comthen your domain is not authenticated. That “via” line is the mail client telling the reader that the message was sent by a service on your behalf, rather than by you.
It appears because the domain that signed the message does not match the domain in your From address. It is visible to every recipient, it looks less trustworthy, and it means DMARC is failing.
Once you complete domain authentication, the “via” disappears.
Fixing it
In the Brevo dashboard, go to your senders and domains settings and authenticate your domain rather than only verifying a sender address. Brevo gives you DNS records — a DKIM record and a Brevo code record, and usually an SPF entry.
Publish them at the DNS host your nameservers point to. This is where most attempts fail: a domain registered with one company and served by another means records added at the registrar are invisible.
Two panel traps to check for:
- Panels that append your domain automatically, turning a full hostname into a doubled one.
- An existing SPF record. Merge Brevo’s mechanism into it — never publish a second record, because a domain may have only one and two means both fail.
Verification usually completes within minutes, though DNS propagation can take longer.
Confirming it worked
Send a test, open it in Gmail, choose Show original, and read Authentication-Results:
spf=pass dkim=pass dmarc=passThen check the inbox display again. No “via” line means the signature now matches your domain.
Other things worth knowing
Free tier daily limits. Brevo’s free plan caps daily sends. For a low-traffic site this is fine; for a store during a sale it is not, and the failure arrives at the worst possible moment. Know your limit before you need it.
Transactional and marketing are separate. Brevo does both, and they use different sending infrastructure and different API endpoints. Order confirmations should go through the transactional path. Sending transactional mail through the marketing path affects deliverability, because the two carry different reputations.
SMTP and API both work. If your host blocks outbound SMTP ports — common — use the API instead, which runs over ordinary HTTPS on port 443. NimblyMail includes Brevo in its free mailer set.
Dedicated IP warm-up. If you take a dedicated IP, it has no sending history and receivers treat it cautiously. Volume needs ramping. For most WordPress sites a shared IP is the better choice, since the pool already carries reputation.
Setting it up, in order
- Authenticate the domain, not just a sender address. This is the step that removes the
vialine and makes DMARC pass. - Publish the records at the right DNS host — wherever your nameservers point, which is often not your registrar.
- Merge, never duplicate, the SPF entry. One SPF record per domain; two means both fail.
- Create an API key and use the API rather than SMTP if your host blocks outbound ports.
- Set your From address to the authenticated domain.
- Send a test and read
Authentication-Results— all three passing, and noviain the inbox display.
Common Brevo errors
| Symptom | Cause | Fix |
|---|---|---|
via ha.d.sender-sib.com shown to recipients |
Domain not authenticated | Complete domain authentication |
| Sender not authorised | From address is not a verified sender or on an authenticated domain | Check the address actually sent, not the configured one |
| Sending stops mid-day | Free-plan daily limit reached | Upgrade, or move transactional mail elsewhere |
| Connection times out | Host blocks outbound SMTP ports | Use the API on port 443 |
| Mail lands in spam despite passing auth | Reputation, or marketing and transactional sharing a domain | Separate the two; check suppressions |
If mail is still filtered after authentication
Once SPF, DKIM and DMARC all pass and the “via” line is gone, configuration is finished and remaining problems are reputation or content. Check Brevo’s own logs for bounces and suppressions before changing anything else — a suppressed address explains a test that fails while customers receive mail normally.
Because authentication depends on DNS records maintained outside your site, it is worth re-checking on a schedule rather than assuming it stays fixed. NimblyMail’s weekly audit re-verifies the records against the mailer you actually have configured and reports the specific one that has gone missing.