Cloudflare Email Routing + Gmail Send As

Before touching any settings, it helps to understand what Cloudflare Email Routing actually does - and what it does not do.

Cloudflare Email Routing is a forwarding service. When someone sends an email to you@yourdomain.com, Cloudflare receives it and forwards it to your Gmail address. That handles the receiving side.

But Cloudflare Email Routing does not handle sending. When you hit reply in Gmail, the email goes out as you@gmail.com - not your custom domain. To send as your domain, you need two additional pieces:

1. An SMTP relay service that provides credentials for sending email through your domain
2. Gmail's Send mail as feature, configured with those SMTP credentials

This guide covers both sides: receiving via Cloudflare, and sending via an SMTP relay integrated with Gmail.

Before starting, make sure you have:

If your domain already uses Cloudflare DNS, skip to Step 2. Otherwise, you need to move your DNS to Cloudflare first.

Add your domain to Cloudflare

1. Go to dash.cloudflare.com and click Add a site
2. Enter your domain name (e.g. yourdomain.com)
3. Select the Free plan
4. Cloudflare will scan your existing DNS records and import them. Review to make sure nothing is missing
5. Cloudflare gives you two nameservers (e.g. aria.ns.cloudflare.com and drake.ns.cloudflare.com)

Update nameservers at your registrar

Log in to your domain registrar and replace the existing nameservers with the two Cloudflare provided. The exact location varies by registrar:

• Namecheap: Domain List > Manage > Nameservers > Custom DNS
• GoDaddy: My Products > DNS > Nameservers > Change
• Porkbun: Domain Management > Nameservers
• Google Domains: DNS > Custom name servers

Enable email routing

1. In Cloudflare dashboard, select your domain
2. Go to Email > Email Routing in the left sidebar
3. Click Get started (or Enable Email Routing)
4. Cloudflare will automatically add the required MX records to your DNS

Cloudflare adds these MX records automatically:

Add a destination address

1. Under Destination addresses, click Add destination address
2. Enter your Gmail address (e.g. yourname@gmail.com)
3. Cloudflare sends a verification email to that address - click the link to confirm

Create routing rules

Now tell Cloudflare which addresses to forward:

1. Go to Routing rules tab
2. Click Create address
3. Set the custom address (e.g. hello@yourdomain.com)
4. Set the destination to your Gmail address
5. Save

You can add as many rules as you want - info@, support@, hello@ - all forwarding to the same Gmail inbox. You can also enable a catch-all rule to forward everything.

Test receiving

Send a test email to your custom domain address from a different email account. It should arrive in your Gmail inbox within a few seconds. Check the email headers to confirm it came through Cloudflare.

To send email as your custom domain from Gmail, you need an SMTP relay service. This is a server that accepts your outgoing email and delivers it on behalf of your domain.

There are several options. Here are the most common ones for personal/small business use:

Example: Setting up smtp2go

We will use smtp2go as the example since it has a generous free tier and straightforward setup. The process is similar for other providers.

1. Create an account at smtp2go.com
2. Go to Settings > Sender Domains and add your domain
3. smtp2go gives you DNS records to add (SPF and DKIM) - we will handle these in Step 5
4. Go to Settings > SMTP Users and create a new SMTP user
5. Save the username and password - you will need these for Gmail

Now connect Gmail to your SMTP relay so you can send email as your custom domain.

Add a "Send mail as" address

1. Open Gmail and go to Settings (gear icon) > See all settings
2. Go to the Accounts and Import tab
3. Under Send mail as, click Add another email address
4. Enter your name and custom email address (e.g. you@yourdomain.com)
5. Uncheck "Treat as an alias" if you want replies to go to your custom address rather than your Gmail address
6. Click Next Step

Enter SMTP credentials

1. SMTP Server: mail.smtp2go.com (or your provider's server)
2. Port: 587
3. Username: your SMTP username from Step 3
4. Password: your SMTP password from Step 3
5. Select Secured connection using TLS
6. Click Add Account

Verify the address

Gmail sends a verification email to your custom domain address. Since you set up Cloudflare Email Routing in Step 2, this email gets forwarded to your Gmail inbox. Open it and click the confirmation link (or enter the code).

Set as default (optional)

Back in Accounts and Import, click make default next to your custom domain address. Now all new emails send from your domain by default.

This is the step most guides get wrong - or skip entirely. Without SPF, DKIM, and DMARC, your emails will likely land in spam. For a deep dive on what these are, read our SPF, DKIM, DMARC guide.

SPF record

SPF tells receiving servers which servers are allowed to send email for your domain. You need to include both Cloudflare (for forwarded email headers) and your SMTP relay.

Cloudflare may have already added a basic SPF record. You need to merge your SMTP relay's include into it. The final record should look like this:

DKIM record

DKIM proves your emails were not tampered with in transit. Your SMTP relay provides the DKIM record to add.

In smtp2go: go to Settings > Sender Domains > your domain. Copy the DKIM CNAME records they provide and add them to Cloudflare DNS.

DMARC record

DMARC ties SPF and DKIM together and tells receiving servers what to do when checks fail. Start with a monitoring policy:

Breaking down the DMARC policy:

• p=none - monitor mode. Emails that fail checks are still delivered, but you get reports
• rua=mailto:... - where to send aggregate reports. Replace with your email

After confirming everything works (give it a week), tighten the policy to p=quarantine (spam folder) or p=reject (bounce).

After adding all DNS records, wait 5-10 minutes for propagation (Cloudflare is fast), then run these checks:

Check 1: Send a test email

1. In Gmail, compose a new email
2. In the From field, select your custom domain address
3. Send it to a different email account (another Gmail, Outlook, etc.)
4. Check that it arrives in the inbox (not spam)

Check 2: Inspect email headers

1. Open the test email you received
2. Click the three-dot menu > Show original
3. Look for these results:

Check 3: Use an online tool

Send a test email to mail-tester.com to get a detailed deliverability score. Aim for 9/10 or higher. Common deductions:

• Missing DKIM alignment (shows as "via" banner)
• Overly permissive DMARC policy (p=none instead of p=reject)
• Missing reverse DNS on the SMTP relay (provider issue, not in your control)

The manual setup works, but it has real pain points. You need to sign up for a separate SMTP relay, manage DNS records across two dashboards, deal with DKIM alignment issues, and troubleshoot deliverability when something changes.

I built SendMailAs because I got tired of doing this myself across a dozen domains. Here is what it replaces:

First domain is free forever. Unlimited domains cost $29/year - less than a single month of Google Workspace.