An SMTP relay your existing app already speaks.
Change four settings and your mailer, CMS, or auth provider sends through Reloop, with delivery logs, webhooks, and bounce handling included. No SDK, no rewrite.
Free plan: 3,000 emails a month. No credit card.
Trusted by 250+ developers
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Four settings.
Zero code changes.
Paste these into any SMTP client. Your Reloop API key is the password, so there is no separate SMTP user to create or rotate.
Works with the mailer
you already have
Framework mailers only need config. Everything else, from queues to templates, keeps working exactly as before.
1import nodemailer from 'nodemailer';2
3const transporter = nodemailer.createTransport({4 host: 'smtp.reloop.sh',5 port: 587,6 auth: {7 user: 'reloop',8 pass: process.env.RELOOP_API_KEY,9 },10});11
12await transporter.sendMail({13 from: 'Acme <receipts@acme.com>',14 to: 'jane@example.com',15 subject: 'Your receipt from Acme',16 html: '<p>Thanks for your order!</p>',17});Plug into any tool
with an SMTP setting
CMSs, auth providers, and dashboards already have an SMTP field. Paste in Reloop and they send like the rest of your app.
More than a relay.
Every message gets the full pipeline.
SMTP sends go through the same delivery stack as the Reloop API. Your mailer doesn't need to know any of it.
- 01AuthenticateA wrong or revoked key is refused at AUTH, so your app sees the error instantly.
- 02Check the senderMail from a domain you haven't verified is rejected before it costs you reputation.
- 03Sign with DKIMEvery message is signed for your domain, so inboxes trust it as yours.
- 04DeliverTLS to the receiving server, smart retries, and your dedicated IP if you have one.
- 05Report backDelivered, bounced, opened, and clicked land in your logs and webhooks.
Know what happened after 250 OK
An SMTP server only tells your app the message was accepted. Reloop shows whether it was delivered, opened, or bounced, and streams every event to your webhooks.
Already have an SMTP provider?
Keep it.
Route any domain through SES, Postmark, Google Workspace, or your own server, and still run templates, automations, and analytics from one place.
- Assign a domain to any SMTP provider in a few clicks
- Credentials are tested before a single email goes out
- Templates, automations, and logs stay in Reloop
- Move a domain back to Reloop SMTP whenever you want
FAQ
Questions before you switch.
Host smtp.reloop.sh, port 587 with STARTTLS, and your Reloop API key as the password. The relay authenticates on the key alone, so any username works; we use reloop in our examples.
Use 587 with STARTTLS unless your client needs something else. 465 is available for implicit TLS, and 2587 and 2465 are alternatives for hosts that block the standard ports.
No. If your app already sends over SMTP, update the host, port, username, and password in its mail config. Queues, templates, and retries in your framework keep working.
Both use the same delivery pipeline, logs, webhooks, and suppression list. SMTP is the fastest way to move an existing app or tool. The API adds things SMTP can't express, like idempotency keys and sending stored templates by id.
Yes. Add your SMTP provider in the dashboard, test the connection, and assign it to a domain. Mail from that domain goes out through your provider while templates, automations, and analytics stay in Reloop.
Yes, each recipient counts once, the same as API sends. The free plan includes 3,000 emails a month with no credit card. Because Reloop is open source, you can also self-host the entire relay.