How to Cloudflare smtp relay

Published October 12, 2024 · Updated July 20, 2026 · SMTP & Deliverability

Search for "Cloudflare SMTP relay" and you will find a lot of confusion — because Cloudflare is famous for CDN and security, not for sending email. So let's clear it up: what can Cloudflare actually do for your email, what it can't do, and how to relay your outgoing mail reliably when you need real sending volume.

Does Cloudflare offer an SMTP relay?

Not in the way most people hope. Cloudflare's Email Routing forwards incoming mail from your domain to another inbox — it is built for receiving, not for sending bulk campaigns. Cloudflare does not provide an outbound SMTP service for blasting newsletters or transactional email at scale. For that you need a dedicated SMTP relay behind your Cloudflare-managed domain.

Receiving

Cloudflare Email Routing

Sending

needs a dedicated SMTP relay

DNS

Cloudflare hosts your SPF/DKIM

How Cloudflare and an SMTP relay work together

Here is the setup that actually works: keep your domain's DNS on Cloudflare, and point your sending through a dedicated SMTP relay. Cloudflare handles the DNS records that authenticate your mail; the SMTP relay handles delivery on a dedicated IP.

Add your sending domain to your SMTP provider.
In Cloudflare DNS, add the SPF, DKIM, and DMARC records the provider gives you.
Point your app or mailer at the relay's SMTP host, port 587, and credentials.
Send — authenticated by the DNS on Cloudflare, delivered by the dedicated relay.

Key point: Cloudflare is your domain's control panel; the SMTP relay is your mail carrier. Using both — Cloudflare for DNS/authentication, a dedicated relay for sending — gives you clean deliverability without hunting for a "Cloudflare SMTP" that does not exist.

Related reading: Gmail mail smtp · Mimecast smtp relay · test your email deliverability

The relay Cloudflare doesn't provide

A dedicated SMTP relay for your domain

Dedicated IP, unlimited sending, and SPF/DKIM/DMARC that drop straight into your Cloudflare DNS. Live in minutes, from $39.99/mo.

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Frequently asked questions

Can I send bulk email through Cloudflare?

No. Cloudflare Email Routing forwards incoming mail; it does not send outbound campaigns. To send bulk or transactional email, use a dedicated SMTP relay and host your authentication records on Cloudflare DNS.

Does Cloudflare provide SPF and DKIM?

Cloudflare hosts the DNS records — you add the SPF, DKIM, and DMARC entries your SMTP provider supplies. That combination is what authenticates your outgoing mail.

What is the best SMTP relay to use with Cloudflare?

One that gives you a dedicated IP, unlimited sending, and ready-to-paste DNS records. You keep DNS on Cloudflare and send through the dedicated relay for reliable inbox placement.