Warming up
Transactional email API
One REST API for the email your users are waiting for, free for 5,000 emails a month and $15 for 50,000. It is sent on a path of its own: Warmerly never sends outreach or warmup through it, and your workspace is isolated from every other sender, so nobody else's bad list can hold up your mail.
Free account, no card required. See pricing
Most of the work is pasting DNS records. The API call is the short part.
For example mail.acme.com. Warmerly registers it for sending and hands you the DNS records for it.
Three DKIM CNAMEs, an MX and an SPF record on a bounce. subdomain, and DMARC. None of them touch your inbound mail, and Verify tells you exactly which record is still missing.
Create a sending key and make one HTTP request, from any language. Every email gets an id you can look up, with its full delivery timeline.
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 }Warmerly is also an outreach tool, so we built this the other way round: the email your users asked for goes out on a path your campaigns can never touch.
bounce. subdomain of yours, so SPF aligns too, and DMARC can pass on both.Each of these is enforced in code, not left to a setting you have to remember.
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.
If a send is throttled or the mail server can't be reached, the email waits and is retried with backoff for up to 24 hours, under the same id. You don't write the retry loop.
When it was accepted for delivery, then delivered, deferred, bounced or marked as spam, with the receiving server's own response. From the API and the dashboard.
Hard bounces and spam complaints join your workspace's suppression list, the same one your campaigns use. Skipped recipients are recorded, so you can see why.
Give your app a sending-only key, optionally limited to one domain. It can't read your email log, change domains, or touch anything else in Warmerly.
Mail goes out from servers in the EU. Warmerly sends no cold outreach or warmup through them.
One email is one recipient. Every plan keeps each email's content for 30 days. Nothing past your allowance is ever charged unless you switch overage on; without it you get 10% extra free, then sends are refused until the next month.
Prices in USD. Tax is added at checkout where it applies.
Every account starts on Free, with no card. Choose a paid plan in the dashboard when you need more.
This is separate from the outreach and warmup plans: a workspace can have either, both or neither.
At every volume Resend publishes, Warmerly costs less, and overage only happens if you turn it on.
Resend is still the better pick if you need an SMTP relay, webhooks, templates or open and click tracking today; those are on our roadmap, not built. The full Resend comparison shows the code change line by line.
Start sending free| Volume | Warmerly | Resend |
|---|---|---|
| Free plan | 5,000 a month, 200 a day | 3,000 a month, 100 a day |
| 50,000 emails a month | $15/mo | $20/mo (Pro) |
| 100,000 emails a month | $29/mo | $35/mo (Pro) |
| 200,000 emails a month | $129/mo | $160/mo (Scale) |
| 500,000 emails a month | $279/mo | $350/mo (Scale) |
| 1,000,000 emails a month | $499/mo | $650/mo (Scale) |
| 2,500,000 emails a month | $899/mo | $1,150/mo (Scale) |
| Overage per 1,000 | $0.60 down to $0.35, only if you switch it on | $0.90 down to $0.46 |
| Dedicated IP | $29/mo on Scale | $30/mo |
Resend prices are those published on resend.com/pricing as of September 2026. Check resend.com for current rates.
Head-to-head pages with prices at four volumes, a feature table, and the cases where the other one is the better pick.
What we commit to in writing. The binding wording is in section 18A of our Terms.
Sending, verification, suppression and delivery tracking are live today. Next up:
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.
Transactional sending infrastructure in the EU, separate from everything else in Warmerly: it never carries cold outreach or warmup. Each workspace is isolated, so a workspace whose bounce or complaint rate gets too high is paused on its own without affecting anyone else.
Inbox providers judge mail partly by where it comes from and by the domain behind it. If password resets shared a sender with a cold campaign that drew complaints, the resets would pay for it. Your outreach and warmup run on your mailboxes; your app's email runs on separate transactional infrastructure. The two never share a sending server or a domain.
A few, all shown in the dashboard ready to copy: three DKIM CNAMEs, an MX and an SPF TXT on bounce.yourdomain (where bounce reports are received), and a DMARC TXT. None of them touch your domain's own inbound mail. The only MX is on bounce.yourdomain, so your mailboxes keep receiving exactly where they do today, and your existing SPF record is left alone.
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. A subdomain of a domain that already receives mail is ideal.
The complaint is reported back to us, the email's status becomes complained, and the address is added to your workspace's suppression list, just like a hard bounce. Later sends to it are skipped and recorded as suppressed.
Free covers 5,000 emails a month (up to 200 a day) with no card. Starter is $15 a month for 50,000, Growth is $29 for 100,000, and Scale runs from $129 for 200,000 to $899 for 2,500,000. Paying yearly gets 2 months free, and visitors in the UK are quoted in pounds. It is a separate subscription from Warmerly's outreach plans: you can have either, both or neither.
One email is one recipient. A message sent to one address counts once; the same message to one address in to and two in cc counts three times. Recipients skipped because they are on your suppression list don't count, and neither does an email that fails on our side before it is handed to the recipient's mail server.
Nothing is charged unless you switch overage on. Without it, you can go 10% past your monthly allowance free, so an unexpected spike doesn't stop password resets mid-month; past that, sends are refused until the next month or until you upgrade. With overage switched on, extra email costs $0.60 per 1,000 on Starter and Growth, falling to $0.35 on the largest Scale plan.
Yes, on any Scale plan, for $29 a month. Most apps don't need one: a dedicated IP's reputation rests on your own sending alone, so it suits senders with high, steady volume. Everyone else is better served by the shared sending infrastructure, where each workspace is still isolated from every other.
3 on Free, 10 on Starter, 25 on Growth and unlimited on Scale. Every domain has to pass SPF, DKIM and DMARC before it can send, and its records are re-checked automatically after that.
On price, yes: at every published volume Warmerly costs less (for example $29 against $35 for 100,000 emails a month, as of September 2026), the free plan is larger, and overage is cheaper and opt-in. Resend is the better pick today if you need an SMTP relay, delivery webhooks, templates or open and click tracking, which Warmerly doesn't have yet, or official SDKs in many languages; Warmerly is a REST API.
If you want to send without building the parts around the sending yourself, yes: domain verification with ready-to-copy DNS records, bounce and complaint handling, a suppression list, retries and a delivery timeline for every email come with it. If you only need raw sending at the lowest possible price and have engineers to build that plumbing, sending through SES directly, at $0.10 per 1,000 emails, is cheaper.
Yes. The transactional email API is covered by a 99.9% monthly availability commitment. If we miss it, you get a service credit on that month's transactional fee: 10% below 99.9%, 25% below 99.0%, 50% below 95.0%. Request it within 30 days by emailing support@warmerly.com. The full terms, including what is excluded, are in section 18A of our Terms of Service.
Not yet. Sending is through the REST API, which any language that can make an HTTP request can call. An SMTP relay, delivery webhooks to your app, templates and open/click tracking are on the roadmap.
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 outreach pricing, the suppression list both products share, or send from a conversation with ChatGPT or Claude.
Create a free Warmerly account, add a sending domain and send your first email from the dashboard. 5,000 emails a month free, no card required.