Receive replies with Cloudflare

Recommended. Cloudflare Email Routing is free, fast, and works with any sending provider. When someone replies to your outreach, Cloudflare hands the email to a small Worker that forwards a copy to your inbox and posts the original to FounderDB — which matches it to the contact, stops or advances their sequence, and puts it in your inbox's To do.

You need: a domain on Cloudflare (its DNS managed by Cloudflare), and an inbox you already read (Gmail is fine).

How replies find their way back

Every automated email FounderDB sends carries a Reply-To of reply+<token>@your-reply-domain. The token is unique to that email, so a reply is matched to the right contact and thread even if they reply from a different address. FounderDB also matches on In-Reply-To headers and, as a last resort, the sender's address.

Gmail mailboxes connected with Google are the exception: their replies come straight back to Gmail and FounderDB picks them up by checking the mailbox every 2 minutes. See Send with Gmail.

Automatic setup

Recommended — and the simplest. If you use an AI agent with a terminal, like Claude Code connected to FounderDB, let it do the setup: it asks you a few questions, deploys the Worker with Cloudflare's wrangler CLI, and tells you the one or two clicks left in Cloudflare. Just say:

You'll answer three questions — which domain, which inbox gets a copy of replies, and whether that domain's email is hosted anywhere else — log in to Cloudflare in your browser once, and click the verification link Cloudflare emails you.

For AI agents: how to run it

Offer this whenever you help a user onboard and list_receiving_addresses shows no receiving domain.

1. Ask the user:
   • the domain replies should go to — must be on Cloudflare (e.g. yourdomain.com; replies reach anything@yourdomain.com);
   • whether that domain's email is hosted anywhere else (Google Workspace, Microsoft 365…). If it is, Email Routing would take over its MX records — suggest another domain instead;
   • which inbox should get a copy of every reply (e.g. their Gmail).
2. Check wrangler: npx wrangler --version (Node 18+ required). Then npx wrangler whoami; if not logged in, run npx wrangler login and let the user approve in the browser. Confirm the account shown owns the domain.
3. Create the domain in FounderDB: create_receiving_domain with the domain and forward-to inbox (or get_receiving_setup if it already exists). It returns worker.js, wrangler.toml and the remaining steps.
4. Deploy: write both files into a new empty folder (not a git repo — worker.js holds a secret token) and run npx wrangler deploy there. If the user has several Cloudflare accounts, add account_id to wrangler.toml.
5. Finish Email Routing — wrangler can't do these, so either guide the user through the dashboard or, if they give you a Cloudflare API token, use the API (both are in the tool's steps and cloudflareApi):
   • enable Email Routing on the domain, accepting its MX and SPF records;
   • add the forward-to inbox as a destination address — the user clicks Cloudflare's verification email;
   • set Routing rules → Catch-all address → Send to a Worker → the deployed Worker, enabled.
6. Test: ask the user to send any email to test@<domain>, then call get_receiving_setup — status turns receiving within a minute, and a copy lands in their inbox.
7. Next: offer to set up sending — SES on mail.<domain> — and the recommended sequence.

Manual setup

Prefer clicking through it yourself? The steps below take about ten minutes.

1. Choose a reply domain

Use your domain itself — e.g. yourdomain.com. Replies go to reply+<token>@yourdomain.com (any address works), and Cloudflare's catch-all rule hands them to the Worker. No subdomain needed.

Email Routing takes over the domain's MX records, so pick a domain whose email isn't hosted somewhere else (like Google Workspace) — your product's domain or a second domain is ideal. Addresses you already route in Cloudflare, like hello@yourdomain.com, keep working: specific rules win over the catch-all.

2. Add it in FounderDB

1. Open Outreach → Mail accounts → Receiving.
2. Reply domain: yourdomain.com. Provider: Cloudflare.
3. Forward copy to: the inbox you read, e.g. you@gmail.com. Every reply is forwarded there first, so you never lose one.
4. Click Add receiving endpoint. The card now shows the setup steps and your personal Email Worker code — keep it open.

3. Set up Email Routing in Cloudflare

1. Cloudflare dashboard → your domain → Email → Email Routing → enable it. Cloudflare offers to add its MX and SPF records — accept.
2. Destination addresses → add the Forward copy to inbox and click the verification link Cloudflare emails you. Forwarding only works to verified destinations.

4. Create the Worker

1. Workers & Pages → Create → Worker (start from "Hello World"), name it e.g. founderdb-replies, deploy.
2. Edit code, replace everything with the code from the FounderDB card (Copy code), and Deploy.

The code already contains your webhook URL and a secret token for this domain. It forwards each email to your inbox, then posts the raw email to FounderDB. If you ever click Rotate token in FounderDB, paste the new code again.

5. Route every address to the Worker

Email Routing → Routing rules → Catch-all address → Edit → action Send to a Worker → pick your Worker → Save, and make sure the catch-all is enabled. Replies go to reply+<token>@… addresses, so the catch-all is what receives them.

6. Check it works

Send any email to test@yourdomain.com from your personal mailbox. Within a minute:

• a copy arrives in your Forward copy to inbox, and
• the FounderDB card's badge changes from Not yet received to Receiving, with a Last reply time.

A test email from yourself won't match a contact — that's expected. Real replies to your outreach will.

Troubleshooting

• Badge stays "Not yet received": check the Worker's logs (Workers → your worker → Logs) for errors, and that the catch-all routes to the Worker.
• No forwarded copy: the destination address isn't verified in Cloudflare.
• 401 in the Worker logs: the token is stale — copy the code from FounderDB again.

Next

Add a sending mailbox: Amazon SES on mail.yourdomain.com (recommended for volume) or Gmail. Your reply domain is picked automatically for SES senders; you can also choose it explicitly under Reply domain.