# Mailchimp Transactional (Mandrill) > Transactional email service from Intuit Mailchimp, formerly Mandrill. It sends application email and SMS through an HTTP API, SMTP or a hosted MCP server, with templates, inbound routing, webhooks and reporting, as a paid add-on to a Mailchimp plan. - Canonical: https://www.anchorterminal.com/tools/mandrill - Markdown: https://www.anchorterminal.com/tools/mandrill.md (~8,850 tokens) - Slim: https://www.anchorterminal.com/tools/mandrill.min.md (~1,930 tokens, same facts, less prose, for token-sensitive contexts) - JSON: https://www.anchorterminal.com/tools/mandrill.json (this page as data, same URL with Accept: application/json) - Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt) - API: https://www.anchorterminal.com/api/v1/index.json - Updated: 2026-10-08 ## Overview **Grade C · 58.1/100 · rank #459 of 722 · #12 in Email delivery APIs · not agent-ready · confidence medium** ## Assessment A public OpenAPI 3.1 file covers all 99 operations, the docs serve Markdown and llms.txt, and keys can be limited by endpoint and IP address. Sending needs a Standard or Premium Mailchimp plan plus $20 blocks of 25,000 emails. No send idempotency key or SLA was found, and the newest dated release is from 24 March 2026. ## Facts | Field | Value | | --- | --- | | Vendor | Intuit Mailchimp (https://mailchimp.com/features/transactional-email/) | | Kind | HTTP API | | Category | Email delivery APIs (https://www.anchorterminal.com/categories/email) | | Transport | HTTP | | Endpoint | `https://mandrillapp.com/api/1.4` | | Auth | API key · Self-serve API key, created in the Transactional web app at mandrillapp.com/settings by an Owner or Admin of the Mailchimp account. The key goes in the JSON body of every POST as `key`, and the MCP server takes it as `Authorization: Bearer`. A key can be limited to chosen endpoints and to IP addresses, and a restricted key needs the AI Agents permission group to use the MCP server. Test keys work only in test mode. There is no OAuth for this API. | | Pricing | Paid ($29.95 / mo) · $20 per block of 25,000 emails a month for 1 to 20 blocks, falling in steps to $10 at 161 blocks or more, on top of a Standard or Premium Mailchimp marketing plan. Blocks are billed monthly in advance and unused emails do not roll over. A dedicated IP is $29.95 a month. An agent's owner can start without a contract through the demo, which gives 500 emails once to the account's own verified domain on any Mailchimp account, free plan included. Test keys send nothing and cost nothing (https://mailchimp.com/pricing/transactional-email/). | | x402 | No · No x402, MPP or L402 in the developer docs, the OpenAPI file or the pricing page (checked 2026-10-08). | | Licence | Proprietary service under Mailchimp's Standard Terms of Use and Additional Terms. The client libraries are under Mailchimp's own client library licence agreement | | Tools exposed | 9 | | Packages | npm: `@mailchimp/mailchimp_transactional`; pypi: `mailchimp-transactional` | | Source | https://github.com/mailchimp/mailchimp-client-lib-codegen | | Docs | https://mailchimp.com/developer/transactional/docs/fundamentals/ | | llms.txt | https://mailchimp.com/developer/transactional/llms.txt | | Last release | 2026-03-24 | | npm downloads / week | 226,039 | | PyPI downloads / week | 132,016 | | API | JSON over HTTP, every call a POST to https://mandrillapp.com/api/1.4/ with the key in the body. 99 operations in an OpenAPI 3.1 file. Output as json, xml, yaml or php. The quick start still uses the 1.0 path, which answered on 8 October 2026 | | MCP server | Hosted at https://mandrillapp.com/mcp over HTTP, 9 tools, API key as a Bearer token. Without a key it answers JSON-RPC error -32001 | | Credentials | API keys created in the web app, several per account, each optionally limited to chosen endpoints and IP addresses. Test keys work only in test mode. No OAuth | | SMTP | smtp.mandrillapp.com on ports 25, 587 or 2525 with STARTTLS, or 465 for SSL. Up to 1,000 recipients a message | | Limits | Hourly sending quota set by reputation and volume, with no published figure. `/messages/search` 20 calls a minute, then 429. Test mode 10,000 messages a day. Demo accounts 25 emails an hour. Scheduling up to one year ahead | | Demo | 500 emails once, to the account's own verified domain only, 25 an hour, 100 inbound a day, no click tracking. Open to free and paid Mailchimp accounts that have not bought blocks before | | Before first send | A Mailchimp account, the Transactional add-on or demo, an API key, and a sending domain verified with DKIM and DMARC records | | Inbound | Add an inbound domain and MX records, then routes post parsed mail to a webhook, in batches of up to 1,000 events about once a minute | | Webhooks | Events batched per URL about once a minute. A failed post is retried up to 20 times at intervals of 15 to 25 minutes | | Data retention | Message content 30 days, bounce details 90 days, raw bounce detail 7 days, backlog 48 hours. The additional terms say retention is not guaranteed | | Client libraries | Node `@mailchimp/mailchimp_transactional` and Python `mailchimp-transactional`, both 1.4.1 from 24 March 2026, plus PHP and Ruby, generated from one specification | | Subaccounts | Separate reputation, reporting and optional fixed hourly quota per sender under one account, managed by API | | Certifications | SOC 2 reports and ISO 27001 per mailchimp.com/about/security. A responsible disclosure programme with no rewards | | Status | status.mailchimp.com, with Mailchimp Transactional as one component since August 2025 and event history by month | | Capabilities | email.send, email.templates, email.inbound, email.domains, email.analytics | | Tags | hosted, paid, mcp, openapi, llms-txt, api-key, smtp, webhooks, inbound, sandbox, typescript, python, status-page, soc2 | | JSON | https://www.anchorterminal.com/api/v1/tools/mandrill.json | ## Score breakdown (methodology v0.4, October 2026 research run) Assessed 2026-10-08 from public evidence against the published checklist (https://www.anchorterminal.com/benchmark/#checklist). Confidence: medium. Performance and Task success pending (no score, not in the total); the total is Σ(score × weight) ÷ 80 over the 7 assessed categories. "This run" is each category's share of the 100 points. | Category | Weight | This run | Score (0–100) | Points | | --- | --- | --- | --- | --- | | Reliability | 16% | 20 | 53 | 10.6 | | Performance | 10% | pending | pending | n/a | | Schema & documentation | 13% | 16.2 | 79 | 12.8 | | Agent ergonomics | 13% | 16.2 | 60 | 9.8 | | Security & auth | 14% | 17.5 | 68 | 11.9 | | Payments & pricing | 10% | 12.5 | 35 | 4.4 | | Task success | 10% | pending | pending | n/a | | Maintenance & community | 7% | 8.8 | 28 | 2.5 | | Transparency & trust (editorial 64, provenance 77) | 7% | 8.8 | 71 | 6.2 | | Negative events | up to −15 | up to −15 | none recorded | 0 | | **Total** | | | | **58.1 → C** | ### Why each score - Reliability 53: Graded on the hosted Transactional API with the hosted lines. status.mailchimp.com lists Mailchimp Transactional as its own component and keeps event history by month (20). In the 90 days to 8 October 2026 it shows three Transactional incidents, all sending delays. They ran about 4 hours 8 minutes on 1 September for some accounts, 4 hours 26 minutes on 15 September and 38 minutes on 17 September. None is described as the API being down, and we count the two long delays together as one major (10). Published numbers cover `/messages/search` at 20 calls a minute, test mode at 10,000 messages a day and the demo at 25 emails an hour. The hourly sending quota is set from reputation with no figure, and no general request limit was found (8). The search endpoint returns 429 and the release notes say to retry 60 seconds after the first of the 20 calls. Mail over the hourly quota is queued in a backlog and not refused. No `Retry-After` header and no idempotency key for sends were found (5). No SLA found, and the additional terms supply the service as-is (0). Generally available (10). - Performance: Pending. Latency is measured per call by our probes, which haven't run yet, so this run doesn't score it. Its weight is shared across the assessed categories until the first probe window closes. - Schema & documentation 79: An OpenAPI 3.1 file with all 99 operations is public at mailchimp.com/developer/openapi/api-reference-2.json, and a Swagger 2.0 copy sits in the client library repository. The link to it in the Transactional llms.txt returns 404 (25). llms.txt for the developer site and for Transactional, and a Markdown copy of every page at the URL plus `.md` (10). Each operation has a summary and a description averaging about 120 characters. They say what a call does and seldom when not to use it (11). Request bodies carry 36 enums, required fields, date patterns and minimum and maximum values. Headers, metadata and merge variables are free-form objects (11). Reference pages show request and response samples with code in eight languages, and each operation lists typed error bodies. The OpenAPI file itself has no examples (13). The version is in the path, but the docs use 1.0, 1.3 and 1.4 in different places, and the public changelog has nothing newer than 19 August 2025, so the move to 1.4 in March 2026 is not in it (9). - Agent ergonomics 60: Graded on the API. `/messages/search` takes a `limit` up to 1,000 and send responses are one small object per recipient. No field selection was found. The hosted MCP server has 9 tools and reaches the 99 operations through `list_api`, `describe_api` and `call_api`, which keeps the definitions small (16). Search filters by date, tag, sender and API key, with no offset or cursor, so larger result sets go through a queued export (10). Errors return `status`, `code`, `name` and `message`, and the fundamentals page pairs common ones with a cause and a fix (16). No idempotency key. Test keys let an agent try sends without delivery, and scheduled messages can be listed and cancelled. We could not read the MCP tool annotations without a key (5). A send needs a key, a sender, a recipient and content. Official libraries for Node, Python, PHP and Ruby (13). - Security & auth 68: API keys are created and revoked in the web app, several to an account, and each can be limited to chosen endpoints and to IP addresses. Keys do not expire and no rotation tooling was found. A new key has full account access by default. The key travels in the JSON body or a Bearer header, not the URL (26). Per-endpoint key permissions, IP limits, test keys that send nothing and subaccounts that can be paused. No approval step for sends or deletes (15). The API and the MCP server return inbound mail and stored message content, which is untrusted text. No guidance on prompt injection was found in the MCP guide or the docs (3). The Account Security page lists the IP addresses that used the account and whether each came by API, SMTP or web, and searches can filter by API key (10). A responsible disclosure programme with no rewards, a security.txt with a contact and no Expires field, SOC 2 reports and ISO 27001 per the security page, and regular penetration tests. No public advisory feed found (14). - Payments & pricing 35: No x402, MPP or L402 (0). Block prices are public without a login, $20 per 25,000 emails falling to $10, and $29.95 a month for a dedicated IP. Full use also needs a Standard or Premium marketing plan, whose price is on a separate page (20). The demo gives 500 emails once on any Mailchimp account, free plan included. We take 5 off because it sends only to the account's own verified domain and we could not confirm that signup asks for no card (15). A person signs up in a browser, enables the add-on, creates a key and sets DNS records, so there is no autonomous route (0). - Task success: Pending. Task success needs the category task suites run through each tool, which haven't run yet, so this run doesn't score it. Its weight is shared across the assessed categories until then. A data provider's data-quality score is published on its listing now and becomes half of this category when it's scored. - Maintenance & community 28: The newest dated release we found is version 1.4.1 of the specification and the Node and Python libraries on 24 March 2026, 198 days before this check (0). No dated Transactional release or changelog entry in the last 90 days. The newest changelog entry is 19 August 2025 (0). A public changelog, a support contact and an API help address in the specification. We saw no public issue replies (6). The Node and Python libraries are both at 1.4.1 and match the current API version, with about 226,000 and 132,000 weekly downloads (15). The generator repository has workflows that validate the specification and build and test each library, and the Node library was updated in February 2024 for an Axios advisory. The test workflow needs a secret key, so we could not see results (7). - Transparency & trust 71: Closed service with published terms and a named contracting entity. The client libraries are source-available under Mailchimp's own licence agreement, which is not an OSI licence (15). The additional terms and the docs agree that sent message content is kept 30 days, the docs add 90 days for bounce details and 48 hours for the backlog, and a data processing addendum dated 26 September 2024 covers deletion. The terms add that retention is not guaranteed (24). No deprecation policy was found, and the API Use Policy says the APIs can change by a posting or an email. Past notices carried dates, such as the TLS 1.0 and 1.1 retirement announced on 5 June 2023 for 18 July 2023 (10). A sub-processor list with locations is public but was last updated on 29 February 2024, and the security page places Mailchimp's own servers in United States data centres (15). Fix list for a coding agent, everything this grade says the listing lacks, the biggest gain first (18 items): https://www.anchorterminal.com/fixes/mandrill.md (JSON https://www.anchorterminal.com/fixes/mandrill.json) ### What we couldn't check - unchecked: the price of the Standard and Premium marketing plans that Transactional requires. The marketing pricing page draws its prices by script - unchecked: whether signing up for a free Mailchimp account to use the demo asks for a payment card - unchecked: the MCP server's tool schemas and annotations, which need an API key to list - unchecked: the key settings page at mandrillapp.com/settings, which is behind a login. Per-endpoint and per-IP key limits are taken from the fundamentals page's error table and the MCP guide - unchecked: the detail pages of the three September 2026 status events, so scope and cause beyond the summaries are not known - Whether any Transactional API change shipped after 24 March 2026. The changelog's newest entry is 19 August 2025 and the docs pages carry no dates - Security incidents in the last 12 months were not searched for beyond the vendor's own pages, because web search was not available - The official MCP registry has no Mailchimp or Mandrill entry under a vendor namespace ### Sources - fundamentals, API conventions, error codes, test mode: (seen 2026-10-08) - Transactional llms.txt and API reference index: (seen 2026-10-08) - OpenAPI 3.1 file for the Transactional API: (seen 2026-10-08) - MCP server guide: (seen 2026-10-08) - MCP endpoint, unauthenticated initialize request: (seen 2026-10-08) - pricing: (seen 2026-10-08) - demo help article: (seen 2026-10-08) - status page: (seen 2026-10-08) - status event history, September 2026 (also 202607, 202608 and 202610): (seen 2026-10-08) - developer release notes: (seen 2026-10-08) - reputation, hourly quota and backlog: (seen 2026-10-08) - activity, reports and retention: (seen 2026-10-08) - quick start and client libraries: (seen 2026-10-08) - Standard Terms of Use: (seen 2026-10-08) - Additional Terms, Transactional Email section: (seen 2026-10-08) - API Use Policy: (seen 2026-10-08) - data processing addendum: (seen 2026-10-08) - sub-processor list: (seen 2026-10-08) - Intuit Global Privacy Statement: (seen 2026-10-08) - security page and responsible disclosure: (seen 2026-10-08) - security.txt: (seen 2026-10-08) - client library generator repository, specification history, workflows and licence: (seen 2026-10-08) - npm package metadata and release dates: (seen 2026-10-08) - PyPI package metadata and release dates: (seen 2026-10-08) - official MCP registry search: (seen 2026-10-08) - RDAP for mandrillapp.com and mailchimp.com: (seen 2026-10-08) ## Who's behind it (provenance 77/100, checked 2026-10-08) | Check | Finding | Points | | --- | --- | --- | | Legal entity named | The Rocket Science Group LLC d/b/a Mailchimp | 20/20 | | Domain age | mailchimp.com, registered 2001-06-29 (25 years) | 15/15 | | Endpoint on the vendor's domain | mandrillapp.com is not on mailchimp.com | 0/15 | | Terms of service | read, states 5 of the 7 things a reader expects, and has 2 clauses that cost points | 4.3/10 | | Privacy policy | read, states 8 of the 8 things a reader expects, and has 1 clause that costs points | 8/10 | | Status page | status.mailchimp.com | 10/10 | | Changelog | published | 10/10 | | security.txt | valid | 10/10 | The Standard Terms of Use, updated and effective 10 October 2025, name The Rocket Science Group LLC d/b/a Mailchimp, 405 N Angier Ave. NE, Atlanta, Georgia, part of the Intuit group with Intuit Inc. as parent. Transactional Email is also governed by the section For Transactional Email (formerly Mandrill) of the Additional Terms at https://mailchimp.com/legal/additional-terms/, which the Standard Terms incorporate, and by the API Use Policy updated 1 August 2023. The privacy field points at the Intuit Global Privacy Statement, last updated 9 March 2026. Mailchimp's terms name it as the privacy document for the service, mailchimp.com/legal/privacy redirects to it, and it names The Rocket Science Group LLC d/b/a Mailchimp. Mailchimp publishes no separate privacy policy. The API and the MCP server are served from mandrillapp.com, registered 2011-09-01, not from mailchimp.com (RDAP, Verisign). mailchimp.com/.well-known/security.txt holds one Contact line that points at the responsible disclosure section of the security page, with no Expires field. mandrillapp.com has no security.txt (404). The changelog covers the Marketing and Transactional APIs together. Its newest entry is dated 19 August 2025. ### Terms and privacy, as read A reading by a fixed set of rules, each answered with the vendor's own sentence. Not legal advice. **Terms of service** (https://mailchimp.com/legal/terms/), read 2026-10-08, gives no date, states 5 of the 7 things a reader expects. - To know. Says it may use customer content to train or improve models, and no opt-out was found (costs points). "We may use your Inputs and Outputs, including Customer Data, for machine learning purposes in order to develop and improve the AI Model, the Services, and similar products and features, and you instruct us to process Customer Data for such purposes." - To know. Says the terms or the service can change without notice (costs points). "Mailchimp may modify, suspend, discontinue, or further limit use of the AI Model at any time (without any notice to you)." - To know. Says access can be ended without notice or for any reason. "We may suspend the Service to you at any time, with or without cause." - To know. Requires arbitration or waives class actions. "The State of Georgia laws and the Federal Arbitration Act will govern all disputes arising out of or relating to the Service and the Agreement, regardless of conflict of laws rules." - Not found in the text. Gives the date it was last updated. - Names the governing law or courts. Disputes go to the courts of Fulton County, Georgia. - Says how changes to the terms are announced. Changes are posted, with no other notice named. - Not found in the text. Refers to a service level or uptime commitment. - Also in the text (2026-10-08). Mailchimp's total liability in any calendar month is capped at what the member paid for the service in the preceding month. "arising out of or relating to the Agreement—whether in contract, tort (including negligence), breach of statutory duty, or otherwise—will be no more than what you paid us for the Service the preceding month." - Also in the text (2026-10-08). Using the AI functions grants Mailchimp an irrevocable, transferable and sublicensable licence over all inputs and outputs. "a worldwide, non-exclusive, irrevocable, transferable, royalty-free, fully paid-up, sublicensable (through multiple-tiers) license to access, use, modify, display, publicly perform, distribute, copy, create derivatives from (including derivative works of) and process any and all Inputs and Outputs" - Also in the text (2026-10-08). After an account is terminated Mailchimp may permanently delete the account and all its data, including campaigns. "Once your account is terminated, you acknowledge and agree that we may permanently delete your account and all the data associated with it, including your Campaigns." **Privacy policy** (https://www.intuit.com/privacy/statement/), read 2026-10-08, dated 2026-03-09, states 8 of the 8 things a reader expects. - To know. Says it may use customer content to train or improve models, and no opt-out was found (costs points). "Improve and develop our products and services by analyzing how they are used and interacted with, by training our artificial intelligence models and other machine learning models" - To know. Says it sells personal data or shares it for advertising. "Intuit may share personal information with advertising networks and other providers to tailor advertising and offers presented to you based on your interactions with the Intuit Platform’s products, services, and offerings." - Gives the date it was last updated. Last updated 2026-03-09. - Says how long data is kept. For as long as needed, with no period named. - Says whether personal data is sold or shared for advertising. Says it does not sell personal data. - Gives a privacy contact. Names a data protection officer. - Says where data is transferred or stored. Relies on standard contractual clauses. - Also in the text (2026-10-08). Data a user shares or brings from third parties is used across the whole Intuit Platform and its products, beyond the single product in use. "Intuit uses that data together to power experiences across the Intuit Platform and products, not just within the individual offering(s) you’re using." - Also in the text (2026-10-08). Session replay tools record user sessions, including clicks, mouse movements, scrolls and keystrokes. "The replays include users’ clicks, mobile app touches, mouse movements, scrolls and keystrokes/key touches during those sessions." - Also in the text (2026-10-08). Data obtained through Google Workspace APIs is not used to develop, improve or train generalised AI or ML models. "Please note any data obtained through Google Workspace APIs is not used to develop, improve, or train any generalized AI and/or ML models." ## Live (updated 2026-10-08 21:53 UTC) - Right now: up, HTTP 404, 442 ms, checked 2026-10-08 21:53 UTC (get on `https://mandrillapp.com/api/1.4`) - Uptime 24h 100.0% (28 probes) · 30 days 100.0% (28 probes) · p50 424 ms · p95 456 ms - Vendor status page: unknown, no machine-readable status found - Always current: https://www.anchorterminal.com/api/v1/live/mandrill.json ## Probe metrics Not measured yet. Our benchmark probes haven't run, so there's no availability, latency or error rate from a run and Performance is pending. Live uptime, where we poll the endpoint, is under Live and doesn't change the score. ## Prices | Item | Price | Unit | Note | | --- | --- | --- | --- | | Email block, 1 to 20 blocks | $0.80 | per 1,000 emails | $20 per block of 25,000 emails, billed monthly, unused emails do not roll over. Needs a Standard or Premium Mailchimp plan | | Email block, 21 to 40 blocks | $0.72 | per 1,000 emails | $18 per block of 25,000 | | Email block, 41 to 80 blocks | $0.64 | per 1,000 emails | $16 per block of 25,000 | | Email block, 81 to 120 blocks | $0.56 | per 1,000 emails | $14 per block of 25,000 | | Email block, 121 to 160 blocks | $0.48 | per 1,000 emails | $12 per block of 25,000 | | Email block, 161 blocks or more | $0.40 | per 1,000 emails | $10 per block of 25,000 | | Dedicated IP | $29.95 | per month (plan) | | Across all listings: https://www.anchorterminal.com/prices/index.md ## Strengths - OpenAPI 3.1 file for all 99 operations, with typed error bodies for 401, 402, 404, 422, 429 and 500 - Hosted MCP server at `https://mandrillapp.com/mcp` with 9 tools, three of which list, describe and call API endpoints - API keys can be limited to named endpoints and to IP addresses, and test keys send nothing - Every docs page has a Markdown copy at the same URL plus `.md`, with an llms.txt index - Status page lists Mailchimp Transactional as its own component with month-by-month event history ## Weaknesses - Full use needs a Standard or Premium Mailchimp marketing plan in addition to the email blocks - No idempotency key on `/messages/send`, and no `Retry-After` header found in the docs or the specification - Three delivery-delay incidents in September 2026, two of them lasting more than four hours - The newest client library and specification release is 24 March 2026, and the changelog's newest entry is 19 August 2025 - The docs give three API version paths (1.0, 1.3 and 1.4), and the llms.txt link to the OpenAPI file returns 404 ## Before you call it (notes for agents) 1. Send every call as POST with the key in the JSON body as `key`. The MCP server takes the same key as `Authorization: Bearer` 2. Use a test API key while building. Test sends are free, capped at 10,000 a day, and deliver nothing 3. Verify the sending domain with DKIM and DMARC first. Mail from an unverified domain is rejected with the reason `unsigned` 4. Keep `/messages/search` under 20 calls a minute and set `limit` (default 100, maximum 1,000). There is no offset, so use an activity export for more 5. For a restricted key that must also use the MCP server, enable the AI Agents permission group on the key ## Connect Install: ```bash npm install @mailchimp/mailchimp_transactional ``` First request: ```bash curl -sS -X POST "https://mandrillapp.com/api/1.0/users/ping" \ --header 'Content-Type: application/json' \ --data-raw '{ "key": "YOUR_API_KEY" }' ``` Claude Code: ```bash claude mcp add --transport http mctx-mcp https://mandrillapp.com/mcp \ -H "Authorization: Bearer YOUR_API_KEY" ``` MCP client configuration: ```json { "mcpServers": { "mctx-mcp": { "headers": { "Authorization": "Bearer YOUR_API_KEY" }, "type": "http", "url": "https://mandrillapp.com/mcp" } } } ``` Through letme (picks today, calling later): https://letme.dev/mandrill. letme answers with the pick and how to call it direct; calling through letme (one key, the vendor's own price) comes later. How it works: https://www.anchorterminal.com/letme/index.md ## Similar tools Ranked by shared capabilities, then score. Same-category tools with no shared capability key are listed last. | Tool | Grade | Score | Rank | Shared capabilities | x402 | Markdown | | --- | --- | --- | --- | --- | --- | --- | | Amazon SES | BB | 75.1 | 48 | email.send, email.inbound, email.templates, email.domains, email.analytics | no | https://www.anchorterminal.com/tools/amazon-ses.md | | Resend API + MCP | BB | 75.1 | 50 | email.send, email.inbound, email.templates, email.domains, email.analytics | no | https://www.anchorterminal.com/tools/resend.md | | MailerSend | B | 69.5 | 156 | email.send, email.inbound, email.templates, email.domains, email.analytics | no | https://www.anchorterminal.com/tools/mailersend.md | | Mailtrap Email API + MCP | B | 66.8 | 228 | email.send, email.inbound, email.templates, email.domains, email.analytics | no | https://www.anchorterminal.com/tools/mailtrap.md | | Postmark API + MCP | B | 66.5 | 235 | email.send, email.inbound, email.templates, email.domains, email.analytics | no | https://www.anchorterminal.com/tools/postmark.md | | Mailgun API + MCP | B | 66.2 | 242 | email.send, email.inbound, email.templates, email.domains, email.analytics | no | https://www.anchorterminal.com/tools/mailgun.md | ## Panel reviews (0) Reviewed by the Anchor panel (https://www.anchorterminal.com/reviewers/index.md): . Desk reviews, written from public documentation, pricing, terms, source and status history on 1 October 2026. No calls made. For a desk review, the outcome says whether the reviewer's questions could be answered from public material: success, partial or failure. How reviews work: https://www.anchorterminal.com/reviews/how-it-works.md ## Notable - The MCP server at https://mandrillapp.com/mcp has 9 tools (account_status, build_template, call_api, describe_api, diagnose_failed_send, integrate_api, list_api, onboarding, submit_feedback) and takes the API key as a Bearer token (source: ) - Transactional Email is an add-on that needs a Standard or Premium Mailchimp plan, and access ends at once if the plan is paused, cancelled or downgraded (source: ) - The demo allows 500 emails once, only to addresses on the account's own verified domain, at 25 an hour, with 100 inbound emails a day (source: ) - Sending speed is set by an hourly quota that Mailchimp calculates from account reputation and volume and says it cannot change by hand. Mail over the quota waits in a backlog for up to 48 hours and is then deleted (source: ) - status.mailchimp.com shows three Transactional incidents in September 2026, sending delays of about 4 hours 8 minutes on 1 September, 4 hours 26 minutes on 15 September and 38 minutes on 17 September (source: ) - The client libraries are under Mailchimp's own client library licence agreement, not an open-source licence (source: ) ## Compare - [Amazon SES vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/amazon-ses-vs-mandrill.md): BB 75.1 vs C 58.1 - [Brevo API + MCP vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/brevo-vs-mandrill.md): E 44.8 vs C 58.1 - [Cloudflare Email Service vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mandrill.md): B 67.3 vs C 58.1 - [Loops API + MCP vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/loops-vs-mandrill.md): B 62.7 vs C 58.1 - [MailerSend vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/mailersend-vs-mandrill.md): B 69.5 vs C 58.1 - [Mailgun API + MCP vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/mailgun-vs-mandrill.md): B 66.2 vs C 58.1 - [Mailjet API + MCP vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/mailjet-vs-mandrill.md): C 59.4 vs C 58.1 - [Mailtrap Email API + MCP vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/mailtrap-vs-mandrill.md): B 66.8 vs C 58.1 - [Mailchimp Transactional (Mandrill) vs Postmark API + MCP](https://www.anchorterminal.com/compare/mandrill-vs-postmark.md): C 58.1 vs B 66.5 - [Mailchimp Transactional (Mandrill) vs Resend API + MCP](https://www.anchorterminal.com/compare/mandrill-vs-resend.md): C 58.1 vs BB 75.1 - [Mailchimp Transactional (Mandrill) vs Twilio SendGrid](https://www.anchorterminal.com/compare/mandrill-vs-sendgrid.md): C 58.1 vs B 63.6 - [Mailchimp Transactional (Mandrill) vs SMTP2GO API + MCP](https://www.anchorterminal.com/compare/mandrill-vs-smtp2go.md): C 58.1 vs D 53.1 - [Mailchimp Transactional (Mandrill) vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mandrill-vs-zoho-zeptomail.md): C 58.1 vs C 61.8 ## Verify this listing For the vendor. The badge or a plain link to this page verifies the listing, from a page on mailchimp.com or one of its subdomains, or the README of github.com/mailchimp/mailchimp-client-lib-codegen. It shows the listing is the vendor's and that the vendor knows it's here, and it never changes a grade, rank or review. The vendor sends the page's address to `POST https://www.anchorterminal.com/api/v1/verify` as `{"slug": "mandrill", "url": "…"}`, or calls the `verify_listing` tool at https://www.anchorterminal.com/mcp. We fetch the page once, then again every week; two failed checks in a row and the verification lapses, and a later pass restores it. What we check: https://www.anchorterminal.com/builders/index.md#verify HTML badge: ```html Mailchimp Transactional (Mandrill) on Anchor Terminal ``` Markdown badge, for a README: ```markdown [![Mailchimp Transactional (Mandrill) on Anchor Terminal](https://www.anchorterminal.com/badges/mandrill.svg)](https://www.anchorterminal.com/tools/mandrill) ``` Plain link: ```html Mailchimp Transactional (Mandrill) on Anchor Terminal ``` ## Share this listing For the vendor. Sharing assets for social media, two PNGs of 1200 × 630 that say Mailchimp Transactional (Mandrill) is listed on Anchor Terminal, with the vendor's logo and this page's address and no grade or score. - Dark: https://www.anchorterminal.com/assets/share/mandrill-dark.png - Light: https://www.anchorterminal.com/assets/share/mandrill-light.png