"Free Graph and Network Visualization Tools (No API Key Required)" matching MCP servers:

A secure email gateway MCP server that protects AI agents from prompt injection attacks by scanning emails for malicious instructions before they reach the agent.

An MCP server for Microsoft Graph, exposing 60 tools across calendar, email, meetings, Teams chat, files, people, directory, tasks, and OneNote over stdio or Streamable HTTP.

Enables controlled Microsoft 365 mail workflows including search, read, thread, attachment, and managed draft operations through Microsoft Graph, without sending or modifying messages.

A modular Model Context Protocol server for Microsoft Graph and Microsoft 365, enabling users to manage Teams, mail, calendar, To Do, contacts, and Outlook settings through natural language.

Enables to manage your Outlook mailbox via Microsoft Graph (write access) with delegated permissions, providing MCP tools to create, modify, and send emails, folders, categories, rules, and automatic replies.

Enables to interact with Nylas API for email, calendar, and contacts via MCP, providing documentation, code samples, and code generation tools.

A collection of MCP servers for Apple macOS apps (Mail, Contacts, Notes, Memory, Messages, Calendar, Reminders) enabling AI assistants to read, search, create, and update data via JXA, SQLite, and EventKit.

A collection of three zero-dependency MCP servers for web scraping via Chrome DevTools Protocol, crypto wallet and price monitoring, and email validation with SMTP sending.

Query your domains, sender compliance status, and Gmail traffic metrics from Claude, Cursor, or any MCP client using the Gmail Postmaster Tools API.

Enables AI agents to access 13 paid micro-tools over x402, paying per request in USDC on Base without API keys or signup. It covers email deliverability, grading, and templates, plus utilities like crypto prices, domain age, hashing, JSON conversion, JWT decoding, regex, slugs, UUIDs, and weather.

Comprehensive email validation MCP server that checks syntax, MX records, disposable domains, role-based accounts, SPF/DKIM, typo suggestions, and risk scoring.

MCP server for inspecting email domains and addresses, providing objective domain-level email infrastructure answers such as MX, SPF, DMARC, MTA-STS, and disposable-domain evidence.

Enables AI assistants to securely operate Microsoft 365 services, including Outlook email drafting/sending, Teams messaging, and user profile retrieval, through MCP over Streamable HTTP. Deployable on Google Cloud Run with managed authentication via Microsoft Entra ID.

A minimal MCP server for sending plain-text emails and managing Gmail user labels over stdio, using only gmail.send and gmail.labels OAuth scopes.

Enables AI assistants to manage Microsoft 365 email, calendar, and contacts through natural language, with zero Azure setup required.

MCP server for email deliverability: validate SPF/DKIM/DMARC/BIMI, check blacklists, test SMTP/IMAP, look up DNS, and generate ready-to-deploy records for any major email provider. Ships with two one-click prompts (audit-deliverability, setup-dns). Public, no auth.

An MCP server that provides AI agents with direct access to authoritative Cakemail API specifications, enabling accurate code generation and eliminating hallucination.

A utility MCP server providing 10 specialized tools for newsletter content preparation and optimization, including subject line generation, HTML-to-text extraction, read time estimation, and email validation. Enables newsletter operators, developers, and content teams to automate pre-send workflows and audit newsletter issues through natural language interactions.

A Model Context Protocol server that provides tools for weather forecasting and Gmail interaction.

Sendmux is an email inbox API and email API for AI agents. Use this MCP server to let authorised agents work with Sendmux mailboxes, inbound email, clean JSON parsing, webhooks, outbound sending, provider routing, logs, billing, and team controls.