by SteadyTabs

Custom domain email in Gmail: Cloudflare Email Routing + Resend

About 20 minutes · Updated September 27, 2026

This guide sets up you@yourdomain.com so that mail arrives in your existing Gmail inbox and you reply from Gmail as that address. It doesn't use Gmail's “Send mail as”, which ends in January 2027. Receiving and typical personal sending volumes are free.

What you need

Step 1: Receive mail with Cloudflare Email Routing

  1. In the Cloudflare dashboard, open your domain, then Email → Email Routing, and enable it. Cloudflare adds the MX and SPF records for you.
  2. Under Destination addresses, add your Gmail address and confirm it from the email Cloudflare sends.
  3. Under Routing rules, create you@yourdomain.com → your Gmail. Optionally, add a catch-all rule.
  4. Send a test message to you@yourdomain.com from another account and check that it shows up in Gmail.

Step 2: Verify your domain in Resend

  1. In Resend, go to Domains → Add domain. Using a subdomain such as send.yourdomain.com for the bounce path is fine. Resend shows the exact records to add.
  2. Add the records Resend lists (a DKIM TXT record, plus SPF/MX records for its bounce subdomain) in Cloudflare DNS. Keep Cloudflare's own Email Routing MX records on the root domain.
  3. Click Verify. It usually takes a few minutes.
  4. Optional but recommended: add a DMARC record such as _dmarc TXT "v=DMARC1; p=none;" if you don't have one.

If your domain already has an SPF record from Email Routing, don't create a second SPF record on the same name. Resend's SPF goes on its bounce subdomain, so the two don't conflict.

Step 3: Create an API key

In Resend, open API Keys → Create API key with Sending access, optionally limited to your domain. Copy it now, because it's only shown once.

Step 4: Send from Gmail

  1. Install CustomFrom in Chrome or Edge.
  2. In its settings, add you@yourdomain.com, choose Resend, and paste the API key. Click Send test email.
  3. Open Gmail and compose a message. Pick your address in the From bar, write as usual, and press Send.

Replies you receive come back through Cloudflare into Gmail. When you answer them, CustomFrom picks your domain address automatically and keeps the reply in the same thread.

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