Category · Communication
Email delivery APIs for AI agents
APIs that send application and transactional email, and often parse inbound mail by webhook. Compared on price per 1,000 emails, deliverability tooling (SPF, DKIM, DMARC, dedicated IPs), inbound handling, sandbox limits and what an agent needs before its first send.
Capability keys email.send · email.inbound · email.templates · email.domains · email.analytics · All tools
letme.dev/email.send picks the top-graded tool in this list and says how to call it direct; calling through letme comes later.
The same listing from the live API. Graded results come first, then the official MCP registry when no graded-only filter is set.
https://www.anchorterminal.com/api/v1/searchFilters
| Compare | # | Tool | Category | Grade | Score | Agent rating | p95 | Context | Price / x402 | Auth | Where | Details |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 38 | Resend API + MCPResend · HTTP API | BB | 75.3 | 3.4 (8) | n/a | n/a | $20 / mo | OAuth or key | Hosted + local | |||
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Transactional and marketing email API with inbound receiving, templates, broadcasts and automations. Top strength
Top weakness 106 MCP tools load at once, with no toolsets |
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| 42 | Amazon SESAmazon Web Services · HTTP API | BB | 75.1 | 3.3 (8) | n/a | n/a | $105 / mo | OAuth or key | Hosted | |||
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AWS's email service for sending and receiving at scale, over the SES v2 API or SMTP, with templates, configuration sets, receipt rules and deliverability tooling. Top strength $0.10 per 1,000 emails a la carte, falling to $0.11 per 1,000 above 100 million on Essentials Top weakness Sandbox limits new accounts to verified recipients and 200 messages a day until production access is granted |
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| 158 | Postmark API + MCPPostmark (ActiveCampaign) · HTTP API | B | 66.7 | 3.0 (2) | n/a | n/a | $15 / mo | API key | Hosted + local | |||
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Transactional email API with separate broadcast streams, templates, inbound parsing and bounce handling. Top strength 24 MCP tools, all with readOnlyHint, destructiveHint and idempotentHint, and descriptions that point to alternatives Top weakness No OpenAPI spec and no published request-rate limit |
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| 161 | Mailgun API + MCPMailgun (Sinch) · HTTP API | B | 66.3 | 3.0 (2) | n/a | n/a | $15 / mo | API key | Hosted + local | |||
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Email sending API with inbound routes, a Forwards API, templates, mailing lists, suppressions and address validation, in US and EU regions. Top strength Key roles (Admin, read-only Analyst, Developer, Support), Domain Sending Keys and IP allowlisting Top weakness 74 MCP tools load by default, each a one-line summary, with no readOnlyHint or destructiveHint |
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| 202 | Twilio SendGridTwilio · HTTP API | B | 63.6 | 2.5 (2) | n/a | n/a | $19.95 / mo | API key | Hosted | |||
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Email API v3 for transactional mail, with Inbound Parse, dynamic templates, suppressions and Marketing Campaigns. Top strength Restricted API keys with per-endpoint scopes, subuser keys and IP access management Top weakness No official MCP server that can send, only Twilio's docs search |
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| 209 | Loops API + MCPLoops (Astrodon Corporation) · HTTP API | B | 63.1 | 3.5 (2) | n/a | n/a | $49 / mo | OAuth or key | Hosted | |||
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Email platform for SaaS companies with one API for contacts, events, campaigns, workflows and transactional email, priced by subscribed contacts rather than sends. Top strength No status incidents in the last 90 days Top weakness No scoped or read-only keys, and no read-only MCP mode |
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| 264 | Mailjet API + MCPMailjet (Sinch) · HTTP API | C | 59.5 | 2.5 (2) | n/a | n/a | $9 / mo | API key | Hosted + local | |||
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Sinch-owned email API with Send API v3.1, SMTP relay, a Parse API for inbound mail, templates and a marketing editor. Top strength SandboxMode on Send API v3.1 validates a payload without delivering it Top weakness The MCP server registers 117 GET-only tools and can't send |
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| 336 | SMTP2GO API + MCPSMTP2GO · HTTP API | D | 53.2 | 3.0 (2) | n/a | n/a | $10 / mo | API key | Hosted | |||
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New Zealand email delivery service with a REST API and SMTP relay, templates, webhooks, subaccounts and SMS. Top strength API keys limited to chosen endpoints, with their own send rate Top weakness Several multi-hour delivery and connectivity incidents since July, and degraded sending on 1 October |
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| 403 | Brevo API + MCPBrevo · HTTP API | E | 45.2 | 2.0 (2) | n/a | n/a | $9 / mo | API key | Hosted | |||
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Transactional email over REST and SMTP relay, with inbound parsing, templates and webhooks, inside a wider marketing and CRM suite (formerly Sendinblue). Top strength POST /v3/smtp/email allows 1,000 requests a second on every plan Top weakness Eight 'multiple services' full outages on the status page since July |
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Nothing matches these filters. .
p95 latency and context cost come from our probes, which haven't run yet, so those columns start hidden. Grades run from AA to F, and agent-ready means BB or better. Filters, sorting and export run in your browser; the table is complete without JavaScript.
Indexed, not reviewed (64)
Listings sorted into this category from public catalogues (the official MCP registry, APIs.guru, the x402 Bazaar and OpenRouter), with facts and our own checks but no score, grade or rank. How the index works.
| Listing | Kind | What it does | Why it's here |
|---|---|---|---|
| Agent Email List — Free SMTP Relay for AI Agents ai.agentemaillist.com | MCP server | Free transactional email + SMTP relay. Agents self-signup, no API key needed to start. | vendor's own |
| Agent Inbox clize.ai | MCP server | A real email inbox for AI agents: human-approved sends, untrusted-by-default inbound. | vendor's own |
| agentsbase — Email for AI Agents agentsbase.net | MCP server | Email for AI agents. Create mailboxes, send/receive emails, and auto-extract verification codes. | vendor's own |
| Apixies Developer API Suite apixies.io | MCP server | 50 developer utility APIs as tools: SSL, DNS, WHOIS, email checks, HTML to PDF, sitemaps and more. | vendor's own |
| ascendkit ascendkit.dev | MCP server | Auth, email, journeys, surveys, webhooks, and analytics for SaaS in one project, one API key. | vendor's own |
| BlackVeil DNS & Email Security Scanner blackveilsecurity.com | MCP server | DNS and email security scanner with 81 MCP tools for SPF, DMARC, DNSSEC, SSL, and brand audits. | vendor's own |
| blackwall blackwalltier.com | MCP server | API-key pre-action risk gate: any irreversible agent action (money, SQL, delete, email). | vendor's own |
| cli kanta.dev | MCP server | Kanta Verify, Find, and Database: email verification, email finding, and B2B contact search. | vendor's own |
| ContrastAPI contrastcyber.com | MCP server | 55 tools, 7 Resources, Sigma rules, email SPF/DMARC, MITRE, CVE/KEV, risk_score. No key. | vendor's own |
| dechonet.com MCP server dechonet.com | MCP server | 20 domain recon tools for AI agents: DNS, SSL, headers, email, subdomains, lookalikes, changes. | vendor's own |
| demipass dustforge.com | MCP server | Credential custody for agents: use secrets blind (ssh/http/smtp/git/db), never in context. | vendor's own |
| Domain & Company Intel MCP datakoot.com | MCP server | Domain intel for AI agents: RDAP registration, DNS, email deliverability, tech stack. | vendor's own |
| domani domani.run | MCP server | Internet identity for AI agents: register or broker domains, email, DNS - pay by card or USDC. | vendor's own |
| dragapp.com MCP server dragapp.com | MCP server | AI-powered email & WhatsApp for teams — manage your shared inbox from Claude, Cursor or ChatGPT. | vendor's own |
| e2a — email for AI agents e2a.dev | MCP server | Authenticated email gateway for AI agents — per-agent inboxes, HITL approval, SPF/DKIM verified. | vendor's own |
| email wraps.dev | MCP server | Send email through your own Amazon SES account, and check domains, suppressions and sandbox status. | vendor's own |
| email-verifier verifox.ai | MCP server | Verify email deliverability & find business emails (single or bulk) via the Verifox API. | vendor's own |
| emailmd emailmd.dev | MCP server | Render markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails. | vendor's own, widely used |
| Eusend eusend.dev | MCP server | Send transactional email and manage domains, audiences, and broadcasts from any MCP client. | vendor's own |
| generect-mcp generect.com | MCP server | B2B lead and company data for AI agents: free audience sizing, search, enrich, emails, phones. | vendor's own |
| gmapsscraper.io MCP server gmapsscraper.io | MCP server | Scrape Google Maps business data from any MCP client — names, phones, emails, websites, ratings. | vendor's own |
| HonkIO honkio.ca | MCP server | Canadian SMS and email API for AI agents: send SMS and email, verify phones, handle CASL consent. | vendor's own |
| Hunter MCP scalably.io | MCP server | Hunter.io MCP: domain search, email finder and verifier, enrichment, discovery, leads. 11 tools. | vendor's own |
| IntoDNS.ai DNS & Email Security Scanner intodns.ai | MCP server | DNS and email security: check SPF, DKIM, DMARC, DNSSEC, DANE and build the records. 45 tools. | vendor's own |
| isMalicious threat intelligence for AI agents ismalicious.com | MCP server | Reputation of IPs, domains, URLs, hashes, emails and phones; CVE lookups; prompt-injection scans | vendor's own |
| Lettio MCP lettio.eu | MCP server | Private, EU-hosted email for AI agents over JMAP: read, search, reply, organize, send. | vendor's own |
| mail spideriq.ai | MCP server | SpiderIQ Mail: SpiderMail mailboxes, messages, threads, send, compose for AI agents | vendor's own |
| Mail7 Email Validation mail7.net | MCP server | Verify email addresses, clean lists, and audit a domain SPF, DKIM, DMARC and MX setup. | vendor's own |
| Mailbuttons (mbag.ai) mailbuttons.com | MCP server | Governed email for AI agents (Mailbuttons / mbag.ai): sandbox inboxes, policy gate, audit log. | vendor's own |
| mailkite mailkite.dev | MCP server | Send email, manage domains, DNS, webhooks, templates, and inbound routing on MailKite | vendor's own |
| Mailrith Email Marketing mailrith.com | MCP server | Manage Subscribers, Broadcasts, Sequences, Automations, and reporting in Mailrith. | vendor's own |
| Mails.ai — Agent Email mails.ai | MCP server | A real inbox for AI agents: send, receive and thread email, behind a prompt-injection firewall. | vendor's own |
| MCP Emails mcpemails.com | MCP server | Never-stored live email: read, send, organize, schedule and auto-triage Gmail or any IMAP mailbox. | vendor's own |
| MobileValidate mobilevalidate.com | MCP server | Check phone numbers (WhatsApp, Telegram, carrier, spam reputation) and e-mail addresses. | vendor's own, widely used |
| monacloud-mcp monacloud.vn | MCP server | Buy .vn/intl domains in VND, deploy apps, Postgres, email, VietQR pay — Vietnam MCP for AI agents | vendor's own |
| multimail.dev MCP server multimail.dev | MCP server | Give your agent its own email address with graduated human oversight, from approval to autonomy. | vendor's own |
| MX Probe mxprobe.dev | MCP server | Email verification for AI agents: send, hold or kill with the reason. Signup and credits by API. | vendor's own |
| nintact nintact.com | MCP server | Contact forms that actually arrive. No SPF/DKIM, no SMTP. AI sorts them and drafts the reply. | vendor's own |
| Nitrosend nitrosend.com | MCP server | AI-native email marketing. Campaigns, automations, transactional, contacts, and analytics. | vendor's own |
| Palisade palisade.email | MCP server | Monitor and manage email authentication (SPF, DKIM, DMARC, MTA-STS, BIMI) for your domains. | vendor's own, widely used |
| Palmyr palmyr.ai | MCP server | Agent infra: email, phone, social, domains, VPS, wallets. Paid per-action via x402, no API key. | vendor's own |
| pntr pntr.dev | MCP server | Free developer subdomains with DNS, catch-all email, and webhook capture, managed via MCP. | vendor's own |
| Postfleet postfleet.ai | MCP server | Give an AI agent its own email address: send, reply, read, and wait for mail. | vendor's own |
| Postio — UK Address, Postcode, Email & Phone Validation postio.co.uk | MCP server | Validate UK addresses, postcodes, emails and phone numbers — Royal Mail PAF, live SMTP and HLR. | vendor's own |
| proxyllm-mcp proxyllm.ai | MCP server | OpenAI-compatible LLM gateway: models, savings math, key provisioning, autonomous email-OTP signup | vendor's own |
| qmailing.com MCP server qmailing.com | MCP server | AI agents read & send email, manage mailboxes, domains and webhooks via the QMailing API. | vendor's own |
| radmail-mcp radmail.ai | MCP server | Email OS for agents - real-inbox search, triage, commitments, and a verifiable BEC hard-stop. | vendor's own |
| ReplyLayer replylayer.ai | MCP server | Safe email for AI agents: a mailbox with inbound scanning, outbound checks and human review. | vendor's own, widely used |
| Salamailer salamailer.fi | MCP server | Send end-to-end encrypted email and files. Encryption happens on your machine, not our server. | vendor's own |
| Samva MCP samva.dev | MCP server | Authenticated Samva email tools, including public documentation and template discovery. | vendor's own |
| sendable sendable.me | MCP server | Send transactional email from your editor — describe the event, Sendable writes and sends it. | vendor's own |
| Sendinel sendinel.ai | MCP server | AI-controlled email ops for campaigns, contacts, segments, analytics, and sending. | vendor's own, widely used |
| sendraven.ai MCP server sendraven.ai | MCP server | Email infrastructure for AI agents: send, read replies as threads, campaigns, per-key limits. | vendor's own |
| sentfrom.ai MCP server sentfrom.ai | MCP server | Email for AI agents: inboxes, send/reply/forward, search, threads, webhooks — 21 SentFromAI tools. | vendor's own |
| siglio-mcp esigndev.com | MCP server | MCP server for Siglio. Lets an AI assistant send documents for e-signature by email or text. | vendor's own |
| templated.email MCP server templated.email | MCP server | Create and manage Templated email templates from any MCP client - bring your own model. | vendor's own |
| truncus.co MCP server truncus.co | MCP server | Send transactional emails from AI agents via Truncus. Validate, track delivery, and manage domains. | vendor's own |
| Val Town val.town | MCP server | Deploy serverless TypeScript on Val Town: HTTP vals, cron, SQLite, email, OAuth. | vendor's own |
| WarmySender warmysender.com | MCP server | AI-agent outreach: cold email, warmup, LinkedIn, Instagram, WhatsApp, verification, 200M leads | vendor's own |
| Worldcitisim eSIM worldcitisim.com | MCP server | Travel eSIMs for 193 countries. Stripe + Bitcoin checkout. QR by email in 30s. No API key. | vendor's own |
The first 60 of 64, most used first. All 64 are in this page's JSON twin and, with their facts, in /api/v1/indexed.json (category).
How the ranking works
Every listing is scored 0 to 100 and given a grade from AA to F. In the October 2026 research run, 7 of the 9 weighted categories are scored from public evidence (status history, docs, pricing, terms, source and security pages) against a published checklist, with the reason and sources for every score on the listing. Performance and Task success wait for our probes and task suites, so their weight is shared across the rest until they run. Negative events deduct up to 15 points. Read the methodology.
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