Forward a Cloudflare Email Routing address to Slack

Steps

1. 1

   Turn on Email Routing for the domain

   The domain has to use Cloudflare DNS. In the Cloudflare dashboard, open Email Routing (Cloudflare's docs currently list it under Compute > Email Service > Email Routing), select Onboard Domain and pick the domain. Cloudflare adds its MX records, an SPF record and a DKIM record. If Email Routing is already on, skip this step.

2. 2

   Add RelayMail as a destination address

   Go to Destination Addresses and enter the forwarding address from your RelayMail setup page (inbox-...@relay.relaymail.app).

3. 3

   Verify the destination

   Cloudflare emails that address a link. RelayMail passes it on to the email on your Slack account; open it and select Verify email address. A routing rule pointing at an unverified destination stays disabled.

4. 4

   Create the routing rule

   Open the domain's Routing Rules tab and select Create routing rule. Set Email pattern to support (or whichever address you use), Action to Send to an email, and Destination to your RelayMail address. Save.

5. 5

   Send a test email

   Email support@ from another account. When it arrives, RelayMail confirms forwarding by itself and it appears in the channel as a new thread; reply there and the sender gets your reply by email.

Confirming the forward

Cloudflare sends a verification email to every new destination address, and rules that point at an unverified destination stay disabled. Until forwarding is confirmed, RelayMail passes that email on to the address on your Slack account, so click Verify email address in it. Destination Addresses can resend it if it went missing. Replies you write in the Slack thread go out from noreply@relay.relaymail.app with Reply-To set to your support address, so the customer's answer comes back through the same forward into the same thread. To send replies as support@ itself, verify your domain in RelayMail (see the custom domain guide); that adds sending records for RelayMail and does not change where your inbound mail goes.

What to watch for

• Onboarding Email Routing replaces the domain's inbound mail path: Cloudflare adds its own MX records and an SPF record (v=spf1 include:_spf.mx.cloudflare.net ~all). If other mail for the domain lives elsewhere, check before you onboard.
• Cloudflare rejects inbound mail that fails the sender domain's DMARC policy or passes neither SPF nor DKIM, and lists restrictive sender DMARC policies as a known cause of failed forwards. It rewrites the envelope sender (SRS) and supports ARC; the From line is unchanged.
• One rule sends to one destination. If two rules share an email pattern, only the first one listed handles mail.
• Limits: 200 routing rules per domain, 200 destination addresses per account, and messages over 25 MiB are rejected.
• Email Routing does not send bounce reports back to the original sender, and mail from senders on realtime block lists is rejected.

Questions