Thanks for signing up.
", text: "Thanks for signing up.", }); ``` No API key to store, no package to install. Errors are thrown with a `code` such as `E_SENDER_NOT_VERIFIED` or `E_RATE_LIMIT_EXCEEDED`. ([Workers API](https://developers.cloudflare.com/email-service/api/send-emails/workers-api/)) Reloop from a Worker is one `fetch` call, or the SDK with the `nodejs_compat` flag. Our [Cloudflare Workers guide](/blog/send-email-cloudflare-workers) covers both: ```typescript // Reloop const reloop = new Reloop({ apiKey: env.RELOOP_API_KEY }); const { response, emailError } = await reloop.mail.send({ from: "AcmeThanks for signing up.
", }); ``` You do store one secret (`wrangler secret put RELOOP_API_KEY`). In return, the same code runs unchanged on Vercel, Fly.io, a Node server or a cron job, and errors come back as values with `message`, `why` and `fix` instead of exceptions. Outside Workers, both have options. Cloudflare offers a [REST API](https://developers.cloudflare.com/email-service/api/send-emails/rest-api/) (`POST /client/v4/accounts/{account_id}/email/sending/send` with a Cloudflare API token) and SMTP. Reloop offers the REST API, SDKs for Node, Python, Go, PHP, Ruby, Rust, Java, .NET and Elixir, and an SMTP relay at `smtp.reloop.sh`. | | Reloop | Cloudflare | |---|---|---| | Workers integration | `fetch` or SDK + secret | Native binding, no secret | | REST API | Yes | Yes | | SMTP | Yes | Yes (beta, port 465) | | Official SDKs | 9 languages | Workers binding | | Errors | Returned as values (`message`, `why`, `fix`) | Thrown, with `code` | | Idempotent retries | `Idempotency-Key` header | Not documented | | Stored templates | Yes | Not documented | Cloudflare caps each email at 50 recipients across to, cc and bcc, and at 5 MiB including attachments ([limits](https://developers.cloudflare.com/email-service/platform/limits/)). New Cloudflare accounts also start on a "conservative daily quota" that grows over time, and higher limits go through a request form. --- ## The DNS requirement Cloudflare's getting-started guide is explicit: **"You must be using Cloudflare DNS to use Email Service."** ([source](https://developers.cloudflare.com/email-service/get-started/send-emails/)) Onboarding a domain adds bounce MX records, SPF, DKIM (selector `cf-bounce._domainkey`) and DMARC on a `cf-bounce` subdomain. ([domains](https://developers.cloudflare.com/email-service/configuration/domains/)) If your DNS is already on Cloudflare, that's a non-issue and setup takes minutes. If it's on Route 53, Google Cloud DNS, Vercel or your registrar, you'd have to move the whole zone just to send email. Reloop works with any DNS provider: publish one DKIM record (`reloop._domainkey`) and merge `include:reloop.sh` into your SPF record. --- ## Events and webhooks Cloudflare publishes six sending events (`message.delivered`, `message.deferred`, `message.bounced`, `message.failed`, `message.rejected`, `message.complained`) **to a Cloudflare Queue**, which you consume with a Worker or an HTTP pull consumer. ([event subscriptions](https://developers.cloudflare.com/email-service/reference/event-subscriptions/)) That's elegant if you're on Workers; from anywhere else you're polling. Reloop pushes signed HTTP webhooks (`email.delivered`, `email.bounced`, `email.complained`, `email.opened`, `email.clicked`, `email.received` and more) to any URL, signed with HMAC-SHA256 in the `Reloop-Signature` header and retried on failure. See [building a webhook delivery system](/blog/building-webhook-delivery-system) for how that works. Both maintain a suppression list for bounces and complaints. Cloudflare's can be scoped per sending domain; Reloop's is shared across transactional mail and campaigns, so one bounce protects both. --- ## Inbound email Cloudflare's [Email Routing](https://developers.cloudflare.com/email-service/get-started/route-emails/) is excellent and free: unlimited inbound mail, forwarded to verified addresses or handed to a Worker's `email()` handler, which can reply in-thread. What you do with the message after that (store it, thread it, search it) is your code. Reloop receives mail into **mailboxes**. Messages are stored, threaded, spam-scored with Rspamd, and readable over the API, the [MCP server](/docs/integrations/ai-tools/mcp-server) or IMAP. Reply in-thread with one call. Hosted plans include 1 inbox on Free, 5 on Pro and 10 on Growth; self-hosted is unlimited. | | Reloop | Cloudflare | |---|---|---| | Receive on your domain | Yes | Yes | | Price | Included per plan | Free, unlimited | | Stored mailboxes with threads | Yes | Build it (for example, Workers + R2) | | Reply in thread | API call | `message.reply()` in a Worker | | MCP and IMAP access | Yes | No | If you're building [AI agents that read and answer email](/blog/build-ai-agent-sends-emails), Reloop gives you the inbox; with Cloudflare you build one. --- ## Marketing, contacts and automations Cloudflare's FAQ is clear: **"Email Service supports transactional email only."** No newsletters, product announcements or drip campaigns. Reloop covers both sides with one suppression list: contacts with custom properties, groups and subscription channels, scheduled broadcast campaigns, and event-triggered automations (`reloop.automations.start`) for onboarding and dunning sequences. See [welcome sequences that convert](/blog/welcome-email-sequences-that-convert). --- ## Lock-in Cloudflare Email Service ties sending to Cloudflare DNS, Workers Paid and, for events, Cloudflare Queues. That's a fine trade if you're committed to the platform. Reloop is Apache 2.0. Start on Reloop Cloud, move to your own server with the [one-command installer](/self-host), and point the SDK's `baseUrl` at your instance. Nothing else in your code changes. --- ## Where Cloudflare is the better choice - **You're all-in on Workers** and your DNS is already on Cloudflare. The binding is the least code you'll ever write to send email. - **You send high transactional volume.** Above roughly 200k emails a month, $0.35 per 1,000 beats our overage rate. - **You only need inbound forwarding.** Email Routing is free and unlimited. - **You want one vendor and one bill** for compute, storage and email. ## Where Reloop is the better choice - **Your DNS isn't on Cloudflare**, or your app runs on more than Workers. - **You send under ~200k a month** and want the lower bill and a real free tier. - **You need marketing mail, templates, contacts or automations** alongside transactional. - **You want inboxes**, for support or AI agents, with MCP and IMAP. - **You want signed HTTP webhooks** instead of a queue consumer. - **You need open source or self-hosting.** - **You need a generally available product today** rather than a beta. --- ## Using both, or switching You don't have to choose all at once. A common setup: keep **Email Routing** for forwarding `hello@` to your team, and send through Reloop from your Workers. To move transactional sending from Cloudflare to Reloop: 1. **Add your domain in Reloop**, publish the `reloop._domainkey` DKIM record and merge `include:reloop.sh` into your SPF record. Don't create a second SPF record. 2. **Store the key** with `wrangler secret put RELOOP_API_KEY`. 3. **Replace `env.EMAIL.send(...)`** with `reloop.mail.send(...)` or the `fetch` helper from our [Workers guide](/blog/send-email-cloudflare-workers). Rename `replyTo` to `reply_to`, and check `emailError` instead of catching exceptions. 4. **Swap the Queue consumer** for a webhook endpoint that verifies `Reloop-Signature`. 5. **Import suppressions** from Cloudflare so you don't email addresses that already bounced or complained. 6. **Ramp traffic** over a few days, then remove the `send_email` binding. --- ## FAQ