Thanks for signing up.
", }, ], }); ``` **Reloop** ```typescript const reloop = new Reloop({ apiKey: process.env.RELOOP_API_KEY! }); const { response, emailError } = await reloop.mail.send({ from: "AcmeThanks for signing up.
", }); ``` The Mailjet SDK throws on failure, so you wrap calls in `try`/`catch`. Reloop returns errors as values. A few more differences: | | Reloop | Mailjet | |---|---|---| | Auth | One API key (`x-api-key`) | API key + secret key (basic auth) | | Field style | `from`, `to`, `html` | `From`, `To`, `HTMLPart` | | Error format | `message`, `why` and `fix` | Status code plus per-message errors | | Template variables | `{{{first_name}}}` | `{{var:first_name}}` with `TemplateLanguage: true` | | React Email | Pass a component or rendered HTML | Pass rendered HTML | | Official SDKs | Node, Python, Go, PHP, Ruby, Rust, Java, .NET, Elixir | Node, Python, PHP, Ruby, Java, Go, C# | Reloop's errors tell you **why** a send failed and **how to fix it**: ```json { "message": "Domain not found", "why": "The domain mail.acme.com was not found or is not authorized for your organization", "fix": "Ensure the domain is registered and verified in your dashboard" } ``` --- ## Receiving email and agent inboxes **Mailjet** handles inbound with its Parse API: you point a domain's MX at Mailjet, and each incoming message is posted to your webhook as JSON. Storing, threading and replying is up to you. **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. Replying in-thread is one call, and an `email.received` webhook is there if you also want push. That matters if you're building: - **AI agents that handle email.** Give an agent an address, let it read the thread and reply. See [build an AI agent that reads and replies to email](/blog/build-ai-agent-sends-emails). - **Support or shared inboxes** where humans and agents work the same threads. - **Reply handling** for transactional mail. | | Reloop | Mailjet | |---|---|---| | Receive on your domain | Yes | Yes (Parse API) | | Stored mailboxes with threads | Yes | No | | Reply in thread via API | Yes | Build it yourself | | MCP access for agents | Yes | No | | IMAP access | Yes | No | --- ## Marketing, contacts and automations This is Mailjet's home ground. It started as a marketing tool, and it shows: - A **drag-and-drop email editor** that marketers can use without touching HTML, plus a brand kit and form builder. - **Segmentation** on Essential, and **automations** and **landing pages** on Premium. - **Subaccounts** to separate brands or clients. Reloop covers the same ground with a developer slant: contacts with custom properties, groups, subscription channels, scheduled broadcast campaigns, and **event-triggered automations** that start when your app tracks an event like `user.signed_up`. Automations are on every plan, including Free. See [welcome sequences that convert](/blog/welcome-email-sequences-that-convert) for a worked example. If the people building your emails are marketers who want a visual editor, Mailjet is the friendlier tool. If they're developers who want templates in code and automations triggered from the app, Reloop fits better. --- ## Deliverability Deliverability mostly comes down to your domain setup and list hygiene. Both cover the basics: SPF and DKIM, bounce and spam-complaint events, open and click tracking, and suppression of bad addresses. The differences: - **Dedicated IPs.** Mailjet offers one on Premium plans of 100k and above, on request. Reloop includes one on Growth at $20 a month. - **Sending path.** Reloop runs its own MTA (KumoMTA) with per-domain throttling and automatic pauses when bounce or complaint rates spike. Read [how bounce processing works](/blog/email-bounce-processing-automation). - **Validation.** Mailjet bundles email validation credits on Essential and Premium. Reloop ships a free [temp email checker](/tools/temp-email-checker) and [domain reputation](/tools/domain-reputation-checker) and [blocklist](/tools/blocklist-checker) checkers. --- ## Self-hosting and lock-in Mailjet is hosted only. Your templates, contacts, logs and suppression lists live in Mailjet's account. Reloop is Apache 2.0. You can: 1. Start on Reloop Cloud. 2. Move to your own server later with the [one-command installer](/self-host) or [Coolify](/blog/reloop-coolify-setup). 3. Keep the same API. Point the SDK's `baseUrl` at your instance and nothing else in your code changes. That helps with data residency, with security reviews that need to read the code handling your users' mail, and as insurance against price changes like September's. Self-hosting isn't free in effort: you own IP reputation, warm-up and uptime. Most teams should start hosted and keep self-hosting as an option. --- ## Where Mailjet is the better choice - **You send under 6,000 emails a month.** Mailjet's free tier is twice Reloop's. - **Marketers build your emails.** The drag-and-drop editor, brand kit, forms and landing pages are built for people who don't write HTML. - **You manage many brands or clients** and want subaccounts in one billing account. ## Where Reloop is the better choice - **You send more than the free tier.** $10 vs $40 at 50k and $20 vs $112 at 100k adds up quickly. - **You want automations without a Premium plan.** - **You need inbound mail as real inboxes**, especially for AI agents. - **You need open source or self-hosting** for compliance, residency or peace of mind. --- ## Switching from Mailjet to Reloop 1. **Add your domain in Reloop** and publish the DKIM record (`reloop._domainkey`). Merge `include:reloop.sh` into your existing SPF record rather than adding a second one. 2. **Swap the client.** Replace `mailjet.post("send", { version: "v3.1" })` with `reloop.mail.send`, and map `From`/`To`/`Subject`/`HTMLPart`/`TextPart` to `from`/`to`/`subject`/`html`/`text`. 3. **Move templates.** Export the HTML from Mailjet and change placeholders to triple braces: `{{var:first_name}}` becomes `{{{first_name}}}`. 4. **Import contacts and suppressions.** Export contacts, unsubscribes and bounced addresses from Mailjet and import them, so you never mail someone who opted out. 5. **Point webhooks** at a new handler. Reloop events are named `email.delivered`, `email.bounced`, `email.complained` and so on, and are signed with HMAC-SHA256 in the `Reloop-Signature` header. 6. **Rebuild automations** as event-triggered automations, and call `reloop.automations.start` from your app where the trigger happens. 7. **Ramp traffic** from 10% to 100% over a week or two, then remove Mailjet's DNS records. Our [SendGrid migration guide](/blog/migrating-from-sendgrid) walks through the same steps in more detail, including a traffic-split flag and a suppression import script. --- ## FAQ