Email: MCP servers, A2A agents and x402 APIs

• mail.halowerk.com Live x402

  DNS and list based verification. Never claims that a mailbox exists without evidence: without an SMTP probe the verdict for a routable address is "unknown", not "valid". (2 paid endpoints on mail.halowerk.com.)

  x402 paid API · 2 endpoints

• Mailrith Email Marketing Live MCP

  Manage Subscribers, Broadcasts, Sequences, Automations, and reporting in Mailrith.

  MCP server · com.mailrith

• Mails.ai — Agent Email Live MCP

  A real inbox for AI agents: send, receive and thread email, behind a prompt-injection firewall.

  MCP server · ai.mails

• MailTester Email Verification Live MCP

  Verify emails (valid/invalid/risky/unknown): MX, SMTP, catch-all, disposable. Free agent key.

  MCP server · com.mailtester

• MAILTYPE — Email Domain Capability Intelligence Live MCP

  Email-domain intelligence: MX capability, provider, disposable status, SPF, DMARC, and MTA-STS.

  MCP server · io.github.GSterlingPress

• MCP Emails Live MCP

  Never-stored live email: read, send, organize, schedule and auto-triage Gmail or any IMAP mailbox.

  MCP server · com.mcpemails

• Moltbot Den Live MCP

  AI agent platform: hosting (VMs, Postgres, Redis, storage), media generation, an inbox per agent.

  MCP server · com.moltbotden

• MyClawn Computer Live MCP

  Your own cloud computer run by an AI agent: signed-in browser, its own email, files, long jobs.

  MCP server · com.myclawn

• netintel.dev Live x402

  Structured live crypto market data for ~50 top assets in one JSON call: spot price and 24h open/high/low/volume/change (Coinbase Exchange) plus market cap, rank and circulating/total/max supply (CoinGecko). Quote in USD…

  x402 paid API · 12 endpoints

• Nulliverba Research Discovery Agent Live A2A

  Read-only discovery agent for unresolved research, independent replication, evidence/provenance work, and structured research contribution formats.

  A2A agent · Unknown · 12 skills

• Oryah Mail Live MCP

  Governed email for agents: Gmail, M365 and IMAP; per-mailbox permissions, send allowlist, audit log

  MCP server · com.infinihash

• OSIR Domain Registrar Live MCP

  Register, renew, transfer, and manage domains, DNS, VPS, and email with 105 tools. By OSIR.

  MCP server · com.osir

• Oveyon Mail Live MCP

  Email for AI agents: send, receive with a safety verdict, reply and approve, as MCP tools.

  MCP server · com.oveyon

• PO6 Mailbox Live MCP

  Give AI agents secure access to your email via private aliases with dedicated mailbox storage.

  MCP server · com.po6

• Postfleet Live MCP

  Give an AI agent its own email address: send, reply, read, and wait for mail.

  MCP server · ai.postfleet

• Powerline Email Tools Live MCP

  Email deliverability checks: SPF, DKIM, DMARC, BIMI, MTA-STS, blacklists, headers, spam words

  MCP server · ai.powerline

• ppu43fkyhimq5fiqpmo42eh5ri0yypid.lambda-url.us-east-1.on.aws Live x402

  Email validation API. Checks whether a string is a syntactically valid email address using the same production-grade validation library trusted across the Node.js ecosystem, catching edge cases a quick regex misses. Ret…

  x402 paid API · 12 endpoints

• Precleared Contact Check Live MCP

  Is this cold email allowed? Per-address verdict, rule quoted, signed receipt. UK, US, CA, DE, FR.

  MCP server · dev.precleared

• primitive.dev Live MCP

  Email infrastructure for AI agents — send, receive, search, and manage email over a clean HTTP API. Connect verified domains, route inbound mail, set up webhooks, and automate email workflows. Authenticate with a Primit…

  MCP server · primitivedotdev

• Prosyo MCP Server Live MCP

  Zero-config Prosyo MCP for LinkedIn, cold email, and inbox. No API key.

  MCP server · io.github.ShubhamTuts

• PumpGTM MCP server Live MCP

  Find buyers, run LinkedIn, email and X outreach, and answer replies from your AI.

  MCP server · com.pumpgtm

• qonoro.ai Live x402

  Validates email deliverability: syntax check, MX record lookup, and SMTP server reachability. Returns risk score and quality rating. Deterministic, sub-second. x402-native. (5 paid endpoints on api.qonoro.ai.)

  x402 paid API · 5 endpoints

• qr.reyn.tools Live x402

  Generate scannable QR codes from any text, URL, or structured payload (WiFi, vCard, SMS, email, geo, crypto). Returns PNG by default with JPG, WebP, and SVG output, plus optional error-correction, sizing, color, version…

  x402 paid API · 1 endpoint

• RadiusOS CRM Live MCP

  34-tool CRM server — contacts, pipeline, quotes, invoices, scheduling, email, and AI scoring.

  MCP server · ai.radiusos.www

• Reach MCP — LinkedIn for AI agents Live MCP

  LinkedIn for AI agents: inbox, invitations, Sales Navigator search, posts, jobs, quotas, webhooks.

  MCP server · com.reachmcp

• Ready APIs Live MCP

  135 MCP tools: geo, email, phone, company, DNS, FX, equities, weather, tax, econ, intel — one key.

  MCP server · com.readyapis

• resolve402.dev Live x402

  Hiring signals of a company: open jobs read from its public ATS board (Greenhouse, Lever, Ashby, SmartRecruiters, Recruitee, Personio, Workable, Teamtailor, Workday), summarized as buying signals (volume, last 30 days,…

  x402 paid API · 9 endpoints

• Scribe Mail Live MCP

  Email signature management finally simple and measurable. Built for teams & AI agents.

  MCP server · com.scribe-mail

• Secret Santa Organizer Live MCP

  Create a Secret Santa party with names, emails, a date, a place, and a budget.

  MCP server · com.secretsantaorganizer

• SendSets Outbound Agent Live A2A

  SendSets is an agent-first outbound platform that lets AI agents create and manage cold email campaigns, add prospects, manage sending accounts, send emails, and inspect campaign results programmatically. Each message c…

  A2A agent · SendSets · 8 skills

• SendSeven Messaging Live MCP

  Unified messaging MCP server: WhatsApp, Instagram, Telegram, SMS, Messenger & email support inbox

  MCP server · com.sendseven

• shield.vainplex.dev Live x402

  ShieldAPI - x402 security preflight before agents accept or store credential material (3 paid endpoints on shield.vainplex.dev.)

  x402 paid API · 3 endpoints

• Signal by StackEnhance Live MCP

  How often 750+ e-commerce brands send marketing emails: counts, send dates, recent subject lines.

  MCP server · com.stackenhance

• Simafri Suite Live MCP

  Professional email, calendar, contacts and files on your own domain.

  MCP server · com.simafri

• SINCOR Agent Swarm Live A2A

  SINCOR is a production-grade autonomous AI workforce platform running 17 specialised skills across 7 archetypes (Scout, Builder, Synthesizer, Negotiator, Director, Auditor, Caretaker). External agents pay in AXIOM (AXM)…

  A2A agent · SINCOR · 12 skills

• sitecheck-api.workers.dev Live x402

  EU VAT number check: format and checksum are tested locally first (a malformed number is rejected with HTTP 400 and no charge), then the official VIES service answers whether it is valid, with the registered name and ad…

  x402 paid API · 12 endpoints

• Space Monkey Mailchimp Dashboard Live MCP

  Mailchimp engagement intelligence for AI agents: campaign analytics and audience insights.

  MCP server · com.igods

• SSSNACK Takeover Arena Live A2A

  An authorized agent hacking arena with scoped HTTP challenges, progressive creative rewards, homepage takeovers, hold leaderboards and IRC help over A2A or MCP.

  A2A agent · SSSNACK · 12 skills

• stable-deepline.dev Live x402

  Enrich Company — merged 30+ field profile from Apollo, Crustdata, and PeopleDataLabs: revenue, headcount, industry, funding, valuation, tech stack, social profiles, SIC/NAICS codes, HQ address. (2 paid endpoints on stab…

  x402 paid API · 2 endpoints

• strale.io Live x402

  OCR on any image via Claude vision. Works on screenshots, photos of documents, handwritten notes. Returns text with confidence. (152 paid endpoints on api.strale.io.)

  x402 paid API · 12 endpoints

• Surfing Dog Inbox Live MCP

  Message, ask for a quote or book a call with Surfing Dog, through its open-source inbox.

  MCP server · ai.surfingdog

• TargetWise — B2B Prospecting & Enrichment Live MCP

  Find companies and B2B contacts, enrich profiles, and look up work emails and business phones.

  MCP server · ai.targetwise

• The Korova Milk Bar Live A2A

  A private, members-only collaboration space for AI agents: rooms, append-only hash-chained messages, DMs, an agent directory with capability tags, and a vouch/flag trust system. Admission requires an agent-speed challen…

  A2A agent · The Korova Milk Bar · 7 skills

• tools.ipintel.ai Live x402

  DNS Lookup API. Resolve domain DNS records and receive structured JSON with A, AAAA, MX, NS, TXT, CAA, and SOA records. Useful for agents, developers, domain diagnostics, email setup checks, DNS troubleshooting, and inf…

  x402 paid API · 8 endpoints

• UGC Agent Live MCP

  Find Instagram and TikTok UGC creators with public emails, and see which brands run UGC.

  MCP server · io.github.VicPitic

• Unlayer: Email, Page & Document Templates for Developers Live MCP

  Generate email, page & PDF document templates as React code (Unlayer Elements) or AI; edit visually.

  MCP server · com.unlayer

• Validate Agent Live A2A

  Security and data-quality guardrails for AI agents. Stop prompt injections before they reach your LLM. Strip PII to stay compliant. Sanitize untrusted HTML without installing dependencies. Validate emails, URLs, JSON sc…

  A2A agent · Validate Agent · 12 skills

• vendsdk.com Live x402

  Follow a public redirect chain with per-hop HTTP status (SSRF-safe) for security agents (14 paid endpoints on vendsdk.com.)

  x402 paid API · 12 endpoints

Related capabilities

x402 paid APIsSocial mediaOn-chain dataAgent infrastructureAI models & inferenceMarketing & SEOResearchWeb scraping

How to use one

MCP servers plug into Claude, ChatGPT, Cursor and other AI clients; A2A agents take tasks over JSON-RPC; x402 APIs charge per call in USDC with no account. Guides: A2A vs MCP · How to call an A2A agent · x402 for agents.

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