Transactional email · Early access

Your app's email, never on a cold‑email IP.

Warmerly transactional email is a REST API for password resets, receipts and notifications. It sends them from mail servers that never carry cold outreach or warmup, so your outreach can never drag the email your users are waiting for into spam.

Get early access Read the API docs

One request to send

1. Add your sending domain, for example mail.acme.com. You get three DNS records to publish.
2. Verify it. Warmerly checks SPF, DKIM and DMARC and tells you which record is still missing.
3. Create a sending key and call the API from your app, in any language that can make an HTTP request.

curl -X POST https://app.warmerly.com/api/v1/transactional/emails \
  -H "Authorization: Bearer wm_tx_…" \
  -H "Idempotency-Key: reset-7f3a9c" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Acme <no-reply@mail.acme.com>",
    "to": "jane@example.org",
    "subject": "Reset your password",
    "html": "<p>Click the link to reset your password.</p>"
  }'

# 202 Accepted
{ "id": "9b1e…", "status": "sent", "duplicate": false }

What you get

Each of these is enforced in code, not left to a setting you have to remember.

Never on a cold-email IP

Transactional mail only leaves from servers set aside for it. If none is available, the API refuses to send; it never falls back to a server that carries outreach or warmup. A campaign's reputation can't put your password resets in spam.

Your DNS, three records

Verify a domain with SPF, DKIM and DMARC. There's no MX record, so your domain keeps receiving mail exactly where it does today. The DKIM key is pinned and never rotated out from under your DNS.

Retries that never double-send

Send an Idempotency-Key header and a repeated request returns the first email instead of sending a second one, even when two retries race each other.

A timeline for every email

Each message records when our server accepted it and when the recipient's server delivered, deferred or bounced it, with the remote server's own response. You get it from the API and the dashboard.

Bounces suppress themselves

A hard bounce adds the address to your workspace's suppression list, the same list your campaigns use. Suppressed recipients are skipped and recorded, so you can see why an email wasn't sent.

Keys that can only send

Transactional keys are separate from the rest of the Warmerly API. Give your app a sending-only key, optionally limited to one domain. It can't read your email log, change domains, or touch your campaigns.

Early access: what isn't built yet

Transactional email is new, and we'd rather you know the gaps before you build on it. If one of these is a dealbreaker, Postmark, Resend or Amazon SES may suit you better today.

An SMTP relay (sending is REST API only for now)
Webhooks that push delivery events to your app
Templates
Open and click tracking

Limits today: 50 recipients per email and 600 emails a minute per workspace.

Questions

What is transactional email?

Email your application sends to one person because of something they did: a password reset, a sign-in link, a receipt, a notification. It is expected and time-sensitive, unlike marketing or cold outreach, which is why it should never share sending reputation with them.

Why keep transactional email off the servers that send cold email?

Inbox providers judge mail partly by the IP it comes from. Cold outreach and warmup build and spend reputation on their IPs; if a campaign draws complaints, everything else leaving that IP suffers. Warmerly sends transactional mail only from servers that carry nothing else, so that can't happen.

Do I need a separate domain?

Use a domain or subdomain you don't send cold outreach from, such as mail.yourcompany.com. Warmerly refuses a domain that is already used for anything else in Warmerly. You publish SPF, DKIM and DMARC records only; your existing inbound mail is untouched.

What does it cost?

Transactional email is in early access and isn't billed separately yet. Its pricing will be published before it's generally available.

Is there an SMTP relay?

Not yet. Sending is through the REST API. An SMTP relay, delivery webhooks to your app, templates and open/click tracking are planned.

Sending cold outreach too? Warmerly's email warmup keeps those mailboxes out of spam, and the free deliverability checker audits any domain's SPF, DKIM and DMARC in seconds. See pricing.

Send your app's email from a clean reputation

Create a free Warmerly account, add a sending domain and send your first email from the dashboard. No card required.

Get early access API docs

Or book a free 15-minute setup call →

Warming up

curl -X POST https://app.warmerly.com/api/v1/transactional/emails \ -H "Authorization: Bearer wm_tx_…" \ -H "Idempotency-Key: reset-7f3a9c" \ -H "Content-Type: application/json" \ -d '{ "from": "Acme <no-reply@mail.acme.com>", "to": "jane@example.org", "subject": "Reset your password", "html": "<p>Click the link to reset your password.</p>" }' # 202 Accepted { "id": "9b1e…", "status": "sent", "duplicate": false }