Warmerly
REST API and webhooks on the Agency plan only; an MCP server on every plan.
Warmerly
Mailivery
One-to-one · API access
API access
One row, in depth: what each tool does, the verified numbers, and who each suits.
Mailivery details read from its pricing page, home page, product pages and API page on 21 October 2026.
Warmerly
REST API and webhooks on the Agency plan only; an MCP server on every plan.
Mailivery
A REST API with webhooks, which its pricing FAQ and placement page say is included on every plan.
The short answer
API access, in one look.
Warmerly offers a REST API and webhooks on the Agency plan only, and an MCP server on every plan. Mailivery's pricing FAQ and placement page say its API is included on every plan, and its API page describes warm-up control, metrics and webhooks for partners with an intro call. Neither publishes full detail: we found no rate limits for Mailivery. Last checked 22 October 2026.
MailiveryMailivery ahead on this row
A REST API with webhooks, which its pricing FAQ and placement page say is included on every plan.
The picture
Drawn side by side.
What each API does
As each page describes it
WarmerlyMailivery
Warmerly
Key on AgencyREST APIHealth webhooksMCP on every plan
Mailivery
API keyStart or pause warm-upAdjust volume and rampWebhooks on events
Warmerly's webhooks send mailbox health events, not opens or replies. Mailivery's pages do not list its webhook events.
How Warmerly does it
Warmerly, in detail.
A REST API and signed health webhooks on Agency, and 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 from Settings
You create a key under Settings, Platform API keys, and send it in an X-Api-Key header to the v1 API. Everything the API does is also in the dashboard.
Warmerly product, checked 21 October 2026
06
A key stops working on downgrade
An API key is accepted only while the workspace is on Agency, so a key stops working for every endpoint after a downgrade. Webhook deliveries pause meanwhile without counting as failures.
Warmerly product, checked 21 October 2026
07
Sixteen event types
Webhook events include score_drop, score_floor, auth_fail, dns_changed, smtp_fail, imap_fail, flagged, auto_paused, auto_resumed, aged_in, marked_dead and the OAuth connect, disconnect and refresh events.
Warmerly product, checked 21 October 2026
08
Workspace-wide events
A subscription receives events for every mailbox in the workspaces you own, across every project, and skips deleted workspaces.
Warmerly product, checked 21 October 2026
09
Verification in the API
Single and bulk email verification, a history list and a usage read are API endpoints, with 402 errors that carry used, limit and upgrade links.
Warmerly product, checked 21 October 2026
10
A trial includes it
The free trial of the Agency plan includes the API, so you can test an integration before paying.
Warmerly product, checked 21 October 2026
How Mailivery does it
Mailivery, in detail.
A REST API for warm-up control and metrics with webhooks, described as available on every plan and offered to partners through a call.
01
What it does
Connect mailboxes, start or pause warm-up, adjust daily volume and ramp-up schedule, read health score, activity logs and deliverability metrics.
mailivery.io/mailivery-api · read 21 October 2026
02
Webhooks
Real-time alerts for mailbox connects and disconnects or warm-up events.
mailivery.io/mailivery-api · read 21 October 2026
03
Documentation
Its API page links to API documentation on readme.io and describes a RESTful API with OpenAPI-style specs.
mailivery.io/mailivery-api · read 21 October 2026
04
Included on every plan
Its pricing FAQ says yes to an API for warm-up, and its placement page says the API is included on every plan.
mailivery.io/pricing · read 21 October 2026
05
A three step start
Its page says to schedule a call, receive an API key and documentation, then deploy and scale.
mailivery.io/mailivery-api · read 22 October 2026
06
Mailbox providers
It lists SMTP, Gmail, Microsoft 365 and SendGrid for mailbox connection through the API.
mailivery.io/mailivery-api · read 22 October 2026
07
Custom templates
The API features list includes building warm-up email templates for more realistic sender behaviour.
mailivery.io/mailivery-api · read 22 October 2026
08
Beyond warm-up
Its warm-up page says the API covers warm-up, inbox placement tests, blacklist monitoring and more.
mailivery.io/email-warm-up · read 22 October 2026
09
Who it targets
It lists cold-email tools and CRMs, marketing agencies and SaaS startups as use cases, and a warm-up page names platforms that embed it.
mailivery.io/mailivery-api · read 22 October 2026
10
Scale claim
It says the API suits agencies, SaaS platforms and sales teams managing 100 or 10,000 inboxes, and that it scales to unlimited mailboxes. We cannot check that.
mailivery.io/mailivery-api · read 22 October 2026
11
Embeddable form
Its home page says larger teams and platforms can get an embeddable web form for onboarding, alongside full API access and high volume limits.
mailivery.io · read 22 October 2026
What Mailivery does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Rate limits
- Authentication details and key scopes
- The webhook event list and retry behaviour
- Whether the API is on every plan, on its API page itself
- Any price for the API or custom high-volume limits
- A public list of endpoints on the marketing pages
- Whether placement tests and blacklist checks have separate API limits
Where the sources disagree
We report each version rather than pick one.
- Plan availability: its API page does not say which plans include the API, while its placement page says included on every plan.
The numbers
Only what we could verify.
| Measure | Warmerly | Mailivery |
|---|---|---|
| API access | REST API and webhooks on the Agency plan only; an MCP server on every plan. | A REST API with webhooks, which its pricing FAQ and placement page say is included on every plan. |
| API on a starting plan | No, Agency only | Stated as every plan |
| Requests a minute | 60 by default, up to 120 | Not stated |
| Webhooks | Health events, Agency plan | Connect, disconnect and warm-up events |
| How you get access | Create a key in Settings on Agency or its trial | Schedule a call, then receive a key |
| Webhook event types | 16 listed health and connection events | Connect, disconnect and warm-up events, no list |
| Mailbox providers in the API | Mailboxes managed through the app | SMTP, Gmail, Microsoft 365, SendGrid |
| AI assistant access | MCP server on every plan | Not stated |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Mailivery is ahead on access
If you want API control of warmup on a small plan, its stated every-plan access is the better offer.
Warmerly has a different API
Ours reads health and manages mailboxes, and the MCP server lets an AI assistant work in your workspace on any plan.
Pause warm-up from code
Mailivery says its API can start, pause and tune warm-up volume and ramp. That suits a platform that wants to warm a customer's mailbox when they connect it. Warmerly's API reads health and manages mailboxes rather than offering that exact control.
Alert a Slack channel
With Warmerly webhooks on Agency you could send score_drop and auth_fail to your own endpoint and post them to chat. Mailivery's webhooks cover connects, disconnects and warm-up events, with no list published.
Working with an AI assistant
An MCP server lets Claude or ChatGPT read a workspace on any plan including Free, with no API key. If you only want to ask questions or make changes in plain words, that is the cheaper route.
Budget a rate limit
A Warmerly key allows 60 requests a minute by default, set from 1 to 120, so a loop over 600 mailboxes at the default takes about ten minutes. Mailivery publishes no limit, so ask before you plan one.
Plan access differs
If you are on Warmerly Growth you need Agency for the API. On Mailivery its pages say every plan has it, so the question there is the call and the key rather than the plan.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You want an MCP server to work with Claude or ChatGPT on any plan
- You need health webhooks and are on or near Agency
- You want signed health webhooks on mailbox events
- You prefer to create a key yourself in settings, with no call
- You want an AI assistant to work in your account without code
Mailivery
Mailivery is the better fit if
- You want API control of warm-up on a lower plan
- You want to start, pause and tune warm-up from code
- You build a product that embeds warm-up and want a partner route
- You want webhook alerts on warm-up events
Questions
Which Warmerly plans include the API?
The Agency plan only. Free, Starter and Growth get an error. An MCP server is on every plan.
Does Mailivery have an API?
Yes. Its pricing FAQ says yes and its placement page says it is included on every plan; its API page gives no plan or rate limits.
How do I get a Warmerly API key?
Create it under Settings, Platform API keys, on the Agency plan or its free trial, then send it as X-Api-Key to the v1 API.
How do I get Mailivery API access?
Its API page says to schedule a call, then receive a key and documentation. Its pricing FAQ says it is available, and its placement page says it is on every plan.
Does Mailivery publish API rate limits?
We found none on its marketing pages. Its documentation is hosted elsewhere and we did not read it.
Sources
- Mailivery API page
- Mailivery pricing
- Mailivery inbox placement test
- Mailivery email warm-up page
- Mailivery home page
Mailivery 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.