"A system or program using SSE instead of STDIO" matching MCP connectors:

Email OS for agents - real-inbox search, triage, commitments, and a verifiable BEC hard-stop.

Verify email deliverability & find business emails (single or bulk) via the Verifox API.

Internet identity for AI agents: register or broker domains, email, DNS - pay by card or USDC.

Check email deliverability for a domain: MX, SPF, DKIM, DMARC, blacklists. Graded, no key.

Scan and fix a domain's email deliverability (SPF, DKIM, DMARC, MTA-STS, BIMI, DNS blocklists).

Email marketing y transaccional AI-native: campañas, correos 1-a-1, contactos, flujos y métricas.

AI-powered virtual assistant that connects to Gmail, Outlook, Slack, Salesforce, HubSpot, Google Calendar, DocuSign, QuickBooks, and 20+ other services. Manage your entire professional life through a single Claude conversation — email, calendar, CRM, documents, travel, expenses, and more.

Phone, SMS & email for AI agents. One remote MCP server (Streamable HTTP, OAuth or API-key auth, no local install) exposing call, sms, email, and event tools; also usable via CLI, Python SDK, and OpenAPI. Self-hostable, AGPLv3.

Open-source MCP server that gives AI agents access to real email and calendar in one npm install. Solves the problem of AI agents hitting a wall when they need your inbox.

Apollo connects your sales data and outreach tools directly to your agent . Ask it to find leads, look up a company, write and send emails, or check how a campaign is performing. All from a conversation, without opening another tab.

Your AI agent just got a marketing team. SendPulse MCP Server provides full access to the SendPulse marketing platform — email campaigns, CRM, chatbots, SMTP, and online courses. 134 methods across 5 modules.

Heldly reads your Google Calendar directly, places tentative holds on every host's calendar, and emails the invitee a one-click picker. The moment the invitee picks, Heldly confirms the chosen slot and deletes the siblings across every host's calendar in the same request. No reusable booking page, no in-app form, no calendar cleanup.

Programmatic email deliverability testing for AI agents. Create inbox placement tests across Gmail, Outlook, Yahoo, Mail.ru, Yandex — get per-provider placement (Inbox/Spam/Promotions), SPF/DKIM/DMARC auth, Rspamd & SpamAssassin verdicts, DNS health, and live SSE results.

Shared inbox and customer support platform for teams. Manage email conversations, assignments, labels, internal notes, contacts, and replies. 29 tools. Connect with your Helpmonks access token.

Disposable test mailboxes on a real domain: send, receive and assert on real email.

MCP server for Nylas — read email, calendars, events and contacts, and send email or create events.

Give an AI agent its own inbox — receive email as a webhook, send over a verified domain.

Email for AI agents — send, receive as a webhook, manage domains, templates, routing.

Turn inbound email into a webhook — verify, parse, route, and store incoming messages.

Send transactional email over a verified domain — templates, attachments, custom headers.