BREVO · TECH STACK
Brevo SMTP: transactional email from EU hosting for SME apps
Brevo (formerly Sendinblue) provides SMTP relay smtp-relay.brevo.com:587 from FR data centres. DKIM/SPF/DMARC, revDSG-aligned, free 300 mails/day, paid from EUR 19/month.
Researched & fact-checked by: DuneDive LLC · As of: 2026-05
What is Brevo?
Brevo is the French email service provider that operated as Sendinblue until May 2023. It offers three function blocks: transactional email (password reset, order confirmation, dunning) via SMTP or REST API, marketing newsletters with lists and automations, and a CRM with contact scoring. For Fairlane and most SME setups, only the first block is operationally relevant: SMTP relay for emails sent by your own applications.
Why not via the own mail server or via Gmail? Because email deliverability has been a hard game since 2024. Gmail and Yahoo introduced strict SPF/DKIM/DMARC requirements in early 2024; Microsoft followed in 2025. A Hetzner server that sends without a dedicated mail-IP reputation lands in the spam folder 60–80% of the time. A mail provider like Brevo, AWS SES, or Postmark has years-built IP pools, dedicated bounce handling, and automatic feedback-loop processing – inbox delivery routinely runs above 95%.
As of May 2026, Brevo hosts in two EU data centres (Paris and Strasbourg, both AWS-eu-west-3 / OVH), is capped at 300 mails per day on the free plan, paid "Starter" begins at EUR 19/month for 20,000 mails per month, "Business" from EUR 49/month with extended automations.
Why it matters
Email delivery is a quiet single point of failure for SME applications. A client login with "forgot password" works only when the Brevo SMTP path is correct, DKIM is set right, and the sender domain is not on a blocklist. Since most tests pass without checking the spam folder, the problem often goes unnoticed for weeks.
Concrete effects for a Swiss SME: a fiduciary platform sends automated quarterly reminders to clients – when 30% land in spam, client trust erodes. An n8n workflow automation emails sales on each new lead – when that fails, leads never arrive. A MyWork.Now platform sends booking confirmations – one client phone call is enough to quantify the damage.
Brevo has another quiet advantage for Swiss setups: the EU hosting can be documented in the TIA and VPVG inventory. No US provider sits in the transit path for transactional mail – for sectors under client confidentiality, that strikes one item off a 5-point list.
How it works
The Brevo SMTP integration has three layers: DNS records, SMTP configuration in the application, and bounce/feedback handling.
DNS records. Four entries in the sender domain Cloudflare DNS, all as DNS-only (grey cloud), not proxied. SPF: `v=spf1 include:spf.brevo.com -all` (or `~all` during rollout). DKIM: Brevo generates a public-key record per domain, entered as TXT under `mail._domainkey.<domain>`. DMARC: `v=DMARC1; p=quarantine; rua=mailto:dmarc-reports@<domain>; pct=100` – start with `p=none` for 14 days of observation, then `quarantine`, later `reject`. MX: unchanged – Brevo is not an incoming mail server, only an outbound SMTP relay.
SMTP configuration. Host `smtp-relay.brevo.com`, port 587 (STARTTLS) or 465 (SMTPS). User: the Brevo account email. Password: a dedicated SMTP key generated in the Brevo dashboard under "Settings → SMTP & API Keys". Important: never use the login password, always a generated key – it can be rotated without changing the account login.
Bounce and feedback loop. Brevo handles hard bounces (non-existent addresses) automatically and removes them from the sending list. Configure a webhook endpoint in the Brevo dashboard to `https://<your-app>/api/email-webhook`; Brevo then POSTs events for delivered, bounce, click, open. The own application then sees which client email was delivered and which was not – compliance-relevant when a client claims they never received a deadline reminder.
Test and monitoring. Mail-Tester.com once per domain before go-live: it must score 10/10, otherwise DKIM/SPF/DMARC is wrong. Then monthly glass-box tests via a GMX/Web.de/Gmail/Outlook test account: do mails land in the inbox? The Brevo dashboard shows delivery rate, bounce rate, and spam rate per domain – a spam rate above 0.3% is a warning sign.
Brevo SMTP setup in 7 steps
- 01Create a Brevo account, confirm the EU hosting option in account settings.
- 02Add the sender domain in the Brevo dashboard; Brevo provides the required DNS records (SPF, DKIM).
- 03Set the DNS records in Cloudflare as DNS-only, wait 24h for propagation.
- 04Set the DMARC record manually, initially p=none, after 14 days of observation move to quarantine.
- 05Generate an SMTP key in the Brevo dashboard (Settings → SMTP & API), store it in the application .env as BREVO_SMTP_KEY.
- 06Configure the application: host smtp-relay.brevo.com, port 587 STARTTLS, user the account mail, pass the SMTP key.
- 07Verify Mail-Tester.com score 10/10, then configure the bounce webhook and monitor delivery rate in Loki/Grafana.
When to use Brevo
Brevo is the right choice when (a) the application sends transactional mail (login, order, invoice, dunning, reminder), (b) the sender domain sits in EU/Switzerland and EU hosting is preferred, and (c) volume is between 300 and 100,000 mails per month – below that the free tier suffices, above that AWS SES (USD 0.10 per 1000 mails, but US hosting) starts to pay off.
Concrete Swiss SME cases: a client platform with 200 login resets per month and 500 quarterly reminders. An n8n workflow automation that emails sales for each new lead – at 50 leads per day, that is 1500 per month. A MyWork.Now booking platform sending confirmations. At Fairlane, Brevo serves 4 domains (fairlane.systems, fairlane.ventures, mywork.now, acquanta.com) and delivers a combined inbox rate of 96–98%.
When not to use
Brevo is the wrong choice when (a) volume exceeds 200,000 mails per month and price-per-mail dominates – AWS SES or MailerSend become cheaper per volume, (b) sub-500 ms delivery latency is required (real-time notifications) – in-app channels or push notifications are better, or (c) heavy marketing sends with complex segmentation rules are needed – Klaviyo or Customer.io fit better.
More pitfalls: running the Brevo free plan in production – the 300/day limit gets hit, a quarterly reminder wave fails silently. Using the Brevo login password as the SMTP password – not rotatable, account lost on leak. Setting DMARC to `p=reject` immediately – before 14 days of observation, a forgotten subdomain SPF will likely block legitimate mail. And ignoring spam complaints – above 0.1% complaint rate Brevo may suspend the account.
Trade-offs
STRENGTHS
- EU hosting in FR – documentable for revDSG/TIA
- Free plan 300 mails/day is enough for prototypes
- DKIM/SPF/DMARC handled in the dashboard, no own mail server work
- Webhook bounce handling out of the box
WEAKNESSES
- Price per mail rises above AWS SES from 100k/month onward
- Suspension on spam complaints above 0.1% – account risk
- Account approval can take hours to days
- Marketing automation is weak compared with Klaviyo
FAQ
What does Brevo cost for an SME?
Free plan: 300 mails/day, about 9,000/month – enough for 1–2 small apps. Starter EUR 19/month: 20,000 mails/month, no Brevo branding in the footer, optional dedicated IP pool. Business EUR 49/month: 100,000 mails plus marketing automation. Above that volume: enterprise pricing, or switch to AWS SES (USD 0.10 per 1,000 mails, but US hosting).
What if mails still land in spam?
Three checks in this order: (1) Mail-Tester.com score – must be 10/10, otherwise check DKIM/SPF/DMARC. (2) Sender reputation – MXToolbox blocklist check per sender IP. (3) Content – too many links, ALL-CAPS TEXT, missing plain-text fallback. At volumes above 5,000 mails/month: book a dedicated IP (Starter plan, EUR 25 extra), warm up the reputation over 4–8 weeks.
Brevo vs AWS SES vs Postmark?
Brevo: EU hosting, EUR 19/month fixed, good UI, useful free tier. AWS SES: USD 0.10 per 1,000 mails, cheap at volume, US hosting (Frankfurt region available as eu-central-1), thin UI. Postmark: USD 15/month for 10,000 mails, very fast delivery, US hosting. For a Swiss SME with revDSG sensitivity: Brevo. For pure cost optimisation with US acceptance: SES eu-central-1.