Warmerly
API and webhooks on Agency only; an MCP server on every plan
Warmerly
Mailshake
One-to-one · Integrations and API
Integrations and API
One row, in depth: what each tool does, the verified numbers, and who each suits.
Mailshake details read from its pricing page, home page, feature pages and help centre on 21 October 2026.
Warmerly
API and webhooks on Agency only; an MCP server on every plan
Mailshake
Native Salesforce, Pipedrive, HubSpot and more; Zapier on all tiers; API access by request
The short answer
Integrations and API, in one look.
Warmerly's API needs the Agency plan and it has no native CRM link, while Mailshake names 32 integrations including Salesforce, Pipedrive and HubSpot, so Mailshake is ahead for CRM links. Mailshake names 32 integrations, with native Salesforce, Pipedrive, HubSpot, Slack, Vidyard, Microsoft and SMTP, and Zapier. Its API is by request, with limits counted in quota units per hour. Warmerly's API and webhooks need the Agency plan, and its webhooks cover mailbox health events only. Warmerly's MCP server is on every plan and lets an AI assistant work in your workspace. For CRM links, Mailshake is ahead. Last checked 22 October 2026.
MailshakeMailshake ahead on this row
Native Salesforce, Pipedrive, HubSpot and more; Zapier on all tiers; API access by request
The picture
Drawn side by side.
What connects to what
Mailshake leads on native CRM links. Warmerly offers an MCP server on every plan.
WarmerlyMailshake
WarmerlyMailshake
- Native CRM links✕None listed✓Salesforce, Pipedrive, HubSpot
- Zapier~Via API key✓All tiers
- API~Agency plan~By request
- Webhooks~Agency, mailbox health?Not mentioned
- MCP server✓Every plan?Not mentioned
y means yes. p means partly or with a condition. n means none. q means not stated on the pages we read.
| Item | Warmerly | Mailshake |
|---|---|---|
| Native CRM links | None listed | Salesforce, Pipedrive, HubSpot |
| Zapier | Via API key | All tiers |
| API | Agency plan | By request |
| Webhooks | Agency, mailbox health | Not mentioned |
| MCP server | Every plan | Not mentioned |
How Warmerly does it
Warmerly, in detail.
An API and signed webhooks on the Agency plan, an MCP server for AI assistants on every plan, and no native CRM connectors.
01
Which plan gets the API
API keys, the API itself and webhooks need the Agency plan, $179 a month for 100 mailboxes. Free, Starter and Growth get a 403 error. The Agency 7-day trial includes API access.
Warmerly product, checked 21 October 2026
02
Rate limit
Each key has its own per-minute limit, 60 requests a minute by default and capped at 120.
Warmerly product, checked 21 October 2026
03
Webhooks are about mailbox health
Outbound webhooks send signed events such as score_drop, auth_fail and auto_paused. They are about mailbox health, not campaign events such as opens or replies, and are Agency only.
Warmerly product, checked 21 October 2026
04
MCP on every plan
Warmerly runs an MCP server so Claude, ChatGPT, Cursor and other clients can read from and act in a signed-in workspace. It signs in with OAuth 2.1, needs no API key and is on every plan including Free.
Warmerly product, checked 21 October 2026
05
Sixteen webhook event types
A subscription picks from 16 event types: score_drop, score_floor, oauth_disconnected, auth_fail, dns_changed, smtp_fail, imap_fail, flagged, auto_paused, auto_resumed, manual_pause, aged_in, marked_dead, oauth_refresh_fail, oauth_connected and oauth_reconnected.
Warmerly product, checked 21 October 2026
06
Webhook limits and safety
Each user can hold at most 10 undeleted subscriptions. The target must be a public https URL, and private, local and reserved addresses are rejected and checked again at delivery. Deliveries pause while the owner is not on Agency, without counting as failures.
Warmerly product, checked 21 October 2026
07
API key handling
A key starts with wmv_ and is shown once. Keys are sent in an X-Api-Key header, most project endpoints also need X-Project-Id, and a revoked key stops working immediately. Listing keys never returns the secret.
Warmerly product, checked 21 October 2026
08
What the API covers
The reference documents accounts, campaigns, leads, verification, the email finder, the inbox, suppression, workspaces and transactional email.
Warmerly product, checked 21 October 2026
09
MCP tools and rate limits
The MCP server registers 37 tools, shares 60 calls a minute per connection across reads and writes, and caps tools that send a message at 20 a minute per connection and 40 a minute per user. Every write is audit logged with the connected app's name.
Warmerly product, checked 21 October 2026
10
An assistant cannot start sending
No MCP tool can launch or resume a campaign. A person presses Launch or Resume in the dashboard, and pausing is allowed because it only reduces activity.
Warmerly product, checked 21 October 2026
How Mailshake does it
Mailshake, in detail.
Native CRM links, calendar, chat, SMS and video connectors, and Zapier, with API access by request and limits that scale with user seats.
01
Integrations named
The integrations page names 32, including Pipedrive, HubSpot, Salesforce, Slack, Google Sheets, Calendly and Zoho. It labels Pipedrive, Slack, SMTP, Vidyard, Microsoft, HubSpot and Salesforce as native.
mailshake.com/integrations · read 21 October 2026
02
Zapier on every tier
The FAQ says all account tiers have access to both native integrations and third party integrations via Zapier. The pricing page lists 1,000+ integrations via Zapier on Email Outreach.
mailshake.com/integrations · read 21 October 2026
03
API by request
The integrations FAQ says to email hello@mailshake.com to request API access. A help article says limits are quota units per hour and recipients added per month, and can be raised by adding user seats.
docs.mailshake.com/article/260-api-limits · read 21 October 2026
04
Webhooks
The integrations page does not mention webhooks, and the help centre lists no webhook article.
mailshake.com/integrations · read 21 October 2026
05
What the 32 cover
The cards span CRM (Pipedrive, HubSpot, Salesforce, Zoho, Copper, Freshsales, Nimble, Salesmate, Salesflare, Agile CRM, WhatConverts), calendars (Calendly, Acuity, ScheduleOnce, HubSpot Scheduling, Google Calendar), chat (Drift, Crisp, LiveAgent, HubSpot chat, Slack), SMS and voice (Twilio, Call Loop, Dialpad), Google Sheets and Forms, Facebook, Vidyard and a connector, Integrately.
mailshake.com/integrations · read 22 October 2026
06
Calendar integrations pause follow-ups
Several calendar cards say a booked meeting can pause emails to that recipient, for example ScheduleOnce, Acuity and Google Calendar. That is automation Warmerly does not list a native link for.
mailshake.com/integrations · read 22 October 2026
07
Where integrations live in the app
The FAQ says to click Extensions near the bottom of the left menu, where native and third-party integrations are managed. New native integrations are announced to its email list, and missing ones can be requested at hello@mailshake.com.
mailshake.com/integrations · read 22 October 2026
08
API limits scale with seats
Limits are quota units per hour and recipients added through the API per month. Each action costs units, and a help article says base limits are multiplied by each user seat. The numbers appear only in the account under Integrations, API, Create API Key.
docs.mailshake.com/article/260-api-limits · read 22 October 2026
09
Zapier triggers named
The follow-ups page says Zapier can trigger emails when a recipient books a meeting, submits a form or when a lead's status changes in Salesforce.
mailshake.com/features/follow-ups · read 22 October 2026
What Mailshake does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Webhooks
- Which plans include the API
- The numeric API limits (shown only in the account)
- Outbound webhooks, or a webhook help article (the help centre categories list API, Zapier, Mailshake.js, Slack and CRMs, and no webhooks)
- The numeric quota units per hour or recipients per month for any plan
- A public API reference page on the pages we read, beyond the help article on limits
- Whether the AI writer or any other feature can be driven from an AI assistant
Where the sources disagree
We report each version rather than pick one.
- The integrations page says to email for API access, while a help article describes a Create API Key screen inside the account.
- Mailshake's pricing cards list Salesforce, Pipedrive, HubSpot and 1,000+ integrations via Zapier under Email Outreach, while its integrations FAQ says all account tiers have access to native and Zapier integrations. We cannot tell which applies to Starter.
The numbers
Only what we could verify.
| Measure | Warmerly | Mailshake |
|---|---|---|
| Integrations and API | API and webhooks on Agency only; an MCP server on every plan | Native Salesforce, Pipedrive, HubSpot and more; Zapier on all tiers; API access by request |
| Native CRM links | None listed | Salesforce, Pipedrive, HubSpot |
| Zapier | Via an API key on Agency | All tiers |
| API | Agency plan, 60 requests a minute by default | By request to hello@mailshake.com |
| AI assistants | MCP server on every plan | Not mentioned |
| Integrations named | No native connectors, API and MCP | 32 cards on the integrations page |
| Webhook events | 16 mailbox health event types, Agency only | Not found |
| MCP tools | 37 tools, on every plan | Not mentioned |
| API limit unit | Requests a minute, 60 by default, 120 at most | Quota units an hour and recipients a month, by seat |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Check your CRM first
If your CRM is Salesforce, HubSpot or Pipedrive, Mailshake has a native link. Warmerly would need the API on Agency or a tool like Zapier.
Webhooks are different
Warmerly's webhooks send mailbox health events, not replies, so do not plan reply automation around them.
Route a reply to Slack
Mailshake lists a native Slack link that sends campaign replies into Slack. On Warmerly there is no native Slack link, and webhooks carry mailbox health events, so a reply alert would have to be built another way, for example from the API on Agency.
Seats and API headroom
Mailshake says base API limits are multiplied by each user seat. A team that buys 3 seats gets three times the base limit, whatever the base is, which is a reason to read your own account screen before planning a sync. Warmerly's limit is per key, 60 requests a minute by default, up to 120.
Ask an assistant to check the mailboxes
With Warmerly's MCP server, a signed-in assistant can read mailbox health and run tools such as a placement test or a warmup switch, within 60 calls a minute. It cannot launch a campaign, so a person still reviews and starts one.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You want an MCP server so Claude or ChatGPT can work in your workspace
- You are on or will move to Agency and want an API and signed webhooks
- You want signed webhooks for mailbox health, and are on or moving to Agency
- You want an assistant connected by OAuth with no API key to store
- You would rather build a link yourself than rely on a fixed list of connectors
Mailshake
Mailshake is the better fit if
- Your CRM is Salesforce, HubSpot or Pipedrive and you want a native link
- You want Zapier on the plan you start with
- You use a calendar tool and want a booked meeting to pause follow-ups
- You want a native Slack, Calendly or Vidyard connector
- You want a published list of connectors you can scan before you buy
Questions
Does Mailshake have an API?
Its integrations FAQ says to email hello@mailshake.com to request API access, and a help article describes API keys and limits.
Does Warmerly have an API?
Yes, on the Agency plan, with webhooks. An MCP server is on every plan.
Does Warmerly have a Salesforce or HubSpot integration?
No native one is listed. The API on the Agency plan, or a tool such as Zapier using an API key, is the route.
Does Warmerly have webhooks for replies or opens?
No. Its webhooks send mailbox health events such as score_drop and auto_paused, and are an Agency feature.
Can an AI assistant send campaigns through Warmerly?
It can read the workspace, draft and use many tools, but no MCP tool can start or resume a campaign. A person does that in the dashboard.
Sources
- Mailshake integrations page
- Mailshake help: API limits (updated 11 January 2022)
- Mailshake pricing page and its FAQ
- Mailshake follow-ups page
Mailshake 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.