Warmerly
REST API and webhooks on the Agency plan only; an MCP server on every plan.
Warmerly
Mailwarm
One-to-one · API access
API access
One row, in depth: what each tool does, the verified numbers, and who each suits.
Mailwarm details read from its pricing page, home page, features page, SMTP warmup page and about page on 21 October 2026.
Warmerly
REST API and webhooks on the Agency plan only; an MCP server on every plan.
Mailwarm
No API is mentioned on the pages we read.
The short answer
API access, in one look.
Warmerly has a REST API and webhooks on the Agency plan only, and an MCP server on every plan. Mailwarm's pages mention no API. Last checked 22 October 2026.
Mailwarm
No API is mentioned on the pages we read.
The picture
Drawn side by side.
Who gets the API
What each says it offers
WarmerlyMailwarm
Warmerly
Agency planAPI key, 60 a minuteSigned health webhooksMCP on every plan
Mailwarm
No API mentioned on the pages we read
Warmerly's keys default to 60 requests a minute, up to 120. An API may exist at Mailwarm and not be described on the pages we read.
How Warmerly does it
Warmerly, in detail.
API and webhooks on Agency, an MCP server for everyone.
01
Agency plan only
API keys, the REST API and webhooks need the Agency plan. Free, Starter and Growth get a 403 error. The Agency 7-day trial includes the API.
Warmerly product, checked 21 October 2026
02
60 requests a minute by default
Each key has its own limit, 60 a minute by default, set at creation from 1 to 120, and capped at 120 on every plan.
Warmerly product, checked 21 October 2026
03
Health webhooks
Signed webhooks send mailbox health events such as score drops, authentication failures and DNS changes. They do not send opens or replies.
Warmerly product, checked 21 October 2026
04
An MCP server on every plan
Claude, ChatGPT and other MCP clients can work in a workspace on every plan, including Free.
Warmerly product, checked 21 October 2026
05
Keys are made in the dashboard
You create a key under Settings, Platform API keys, name it, and copy it straight away. It starts with wmv_ and is shown once. If you lose it you revoke it and make another. Requests go to app.warmerly.com/api/v1 with an X-Api-Key header, plus an X-Project-Id header for project endpoints such as mailboxes and campaigns.
Warmerly product, checked 21 October 2026
06
Try the API before paying
A free trial of the Agency plan includes API access, so you can test an integration before the first charge. On other plans the keys page says API access is an Agency plan feature, and calls answer 403 with the code agency_plan_required.
Warmerly product, checked 21 October 2026
07
Sixteen webhook event types
A subscription can ask for events such as score_drop, score_floor, auth_fail, dns_changed, smtp_fail, imap_fail, flagged, auto_paused, auto_resumed, aged_in and marked_dead, plus the sign-in events oauth_connected, oauth_reconnected, oauth_disconnected and oauth_refresh_fail. A subscription receives events for every mailbox in the workspaces you own.
Warmerly product, checked 21 October 2026
08
Webhooks stop when the plan does
Deliveries pause while the owner is not on the Agency plan, without counting as failures. A key also stops working for every endpoint after a downgrade, although revoking a key is never blocked.
Warmerly product, checked 21 October 2026
09
A documented error shape
Authenticated errors come back as JSON with a stable code, a short message and optional details, with codes such as unauthorized, forbidden, not_found, conflict and too_many_requests. A plan limit shows as a 402, and a rate limit as a 429.
Warmerly product, checked 21 October 2026
10
A public deliverability check endpoint
A public, unauthenticated deliverability check endpoint exists, alongside the free tools on warmerly.com. It needs no key, and its errors are plain strings rather than the object shape.
Warmerly product, checked 21 October 2026
11
An MCP server on every plan
The MCP server at /api/mcp lets an assistant such as Claude or ChatGPT read, and act in, a signed-in person's workspace. It uses an OAuth 2.1 sign-in and stateless HTTP, and it is on every plan, including Free.
Warmerly product, checked 21 October 2026
How Mailwarm does it
Mailwarm, in detail.
No API is mentioned on the pages we read.
01
Nothing found
Its pricing, home and features pages do not mention an API, webhooks or alerts.
mailwarm.com/features · read 21 October 2026
02
The developer page names no API
Its page for developers says the product is made for developers and works on autopilot, and names transactional services, custom stacks and SMTP as supported sending methods. It does not mention an API, webhooks, an SDK or developer documentation.
mailwarm.com/email-warmup-for-developers · read 22 October 2026
03
No server details for SMTP
The same page gives no SMTP server details, ports, authentication methods or setup steps beyond sign up, link an email account and start the warm-up.
mailwarm.com/email-warmup-for-developers · read 22 October 2026
04
An API appears once, as a use case
Its free email checker lists API integrations among the uses for verification. The page does not describe the API, its limits or its price.
mailwarm.com/email-checker · read 22 October 2026
05
Free tools and generators instead
What it does publish for people who work in DNS is a set of free tools and generators: 12 checkers, including SPF, DKIM, DMARC, MX, reverse DNS and an email header analyser, and 6 generators for SPF, DKIM, DMARC, signatures, Gmail and email addresses.
mailwarm.com · read 22 October 2026
06
Two sign-in links, no developer area
The site links to app.mailwarm.com for login and registration. No developer portal, API reference or status page is linked from the pages we read.
mailwarm.com · read 22 October 2026
07
Affiliate programme as the only partner route
Its partner page offers 50% commission on a referral's first purchase and 25% a month while the referral stays subscribed. It describes no integration partner programme.
mailwarm.com/affiliates · read 22 October 2026
What Mailwarm does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Any API or webhook
- Rate limits
- Any integration beyond mailbox providers
- Whether an API exists behind the login
- Any webhook, event or alert subscription
- Whether usage or placement data can be exported
- A rate limit, key type or authentication method for developers
- A status page or uptime commitment
The numbers
Only what we could verify.
| Measure | Warmerly | Mailwarm |
|---|---|---|
| API access | REST API and webhooks on the Agency plan only; an MCP server on every plan. | No API is mentioned on the pages we read. |
| API on a starting plan | No, Agency only | Not mentioned |
| Requests a minute | 60 by default, up to 120 | Not stated |
| Webhooks | Health events, Agency plan | Not mentioned |
| Webhook event types | 16 | Not mentioned |
| Try the API before paying | Yes, on the Agency trial | Not mentioned |
| Key prefix and header | wmv_, sent as X-Api-Key | Not mentioned |
| AI assistant access | MCP server on every plan | Not mentioned |
| Free DNS checkers | Free tools on warmerly.com | 12 checkers and 6 generators |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Absence on its pages is not proof
An API may exist and not be described on the pages we read. Ask Mailwarm before you rely on either answer.
Alerts without an API
If all you want is to hear that a mailbox has broken, you do not need an API on Warmerly: it emails an alert when a listing or a hard failure is found. The webhooks matter when you want the same event in your own system, for example to open a ticket when a score drops.
Agency is the price of the API
The API costs the Agency plan, $179 a month for 100 mailboxes. A team with 5 mailboxes that wants a webhook pays 179 rather than 19, which is a reason to use the dashboard and email alerts unless the integration is worth the step up. Warmerly does not sell the API on its own.
Test first, then decide
Because the Agency trial includes the API, a 7-day test costs nothing until day 8. You can create a key, list your mailboxes with one request and subscribe a webhook to see whether the payload fits your tool before you commit.
What the webhooks do not send
Warmerly's webhooks carry mailbox health events. They do not send opens or replies, so a reply-driven automation would read the inbox through the API or the dashboard instead.
Absence on a page is not proof
Mailwarm may have an API that its public pages do not describe. We looked at its home, pricing, features, developer, SMTP and checker pages. If an integration matters to you, ask its team a direct question and get the answer in writing.
Keys and plans move together
If an Agency subscription ends, every API key stops working at once, although you can still revoke them. Plan for that before you point production code at a key.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You want a documented API and signed health webhooks on the Agency plan
- You want an MCP server on every plan
- You want signed webhooks for mailbox health events in your own system
- You want an assistant such as Claude or ChatGPT to work in your workspace
- You want to test an API during a trial before you pay
Mailwarm
Mailwarm is the better fit if
- You do not need an API
- You only need warmup and monitoring from a dashboard, with no code
- You want free DNS checkers and generators next to the service
Questions
Does Mailwarm have an API?
Its pricing, home and features pages mention none. It may exist; we could not confirm it.
Does Mailwarm have webhooks?
None are described on the pages we read. Its developer page does not mention an API, webhooks or documentation (mailwarm.com/email-warmup-for-developers, read 22 October 2026).
Which Warmerly plans include the API?
Agency only, plus the Agency free trial. Free, Starter and Growth get a 403 with agency_plan_required.
What can Warmerly's webhooks tell me?
Mailbox health events: score drops, authentication and connection failures, DNS changes, auto pauses and resumes, aged-in and marked-dead. They do not send opens or replies.
Can I connect Claude or ChatGPT to Warmerly?
Yes, through the MCP server, which is on every plan. It uses an OAuth sign-in, and you choose which workspace it can use.
Sources
- Mailwarm pricing
- Mailwarm home page
- Mailwarm features
- Mailwarm email warmup for developers
- Mailwarm email checker
- Mailwarm affiliates
Mailwarm pages were read on 21 October 2026. Plans and wording change, so check the vendor's own page before you decide. Warmerly details come from the product as it runs today.
More features
See it on your own mailbox.
Connect a mailbox. Warmerly runs alongside whatever you send from now, so you can compare before you move anything.
Free plan, no card. Paid plans: 7-day trial, first charge on day 8.