Guide

What is MCP (Model Context Protocol)?

MCP, the Model Context Protocol, is a common way for AI applications to talk to tools. It does for AI tools what USB did for peripherals: one plug, many devices.

Updated 2026-10-02 · Emailsify

The problem it solves

Before MCP, every AI app needed custom code for every service. MCP defines one interface: a server exposes tools, and any compatible client can discover and call them.

The moving parts

  • Client: the AI app (Claude Code, Cursor and similar).
  • Server: a program that exposes tools, such as Emailsify.
  • Tools: named functions with typed inputs, for example one that creates a fresh inbox.
  • Transport: stdio for local servers, or HTTP for hosted ones.

Why it fits email

An agent can then ask for an address, trigger a signup and wait for the code using the same standard tool calls as everything else it does.

Frequently asked questions

Who created MCP?

Anthropic introduced it as an open protocol, and many tools now support it.

Do I need to code to use it?

Usually not: you add a server's URL or command to your client's settings.

Keep reading

How to give an AI agent an email addressThree ways to give an agent an inbox and the trade-offs: your real mailbox, a shared account, or a temporary inbox with tool access.How to set up the Emailsify MCP server in Claude CodeAdd the hosted Emailsify MCP server to Claude Code with one command, sign in, and give your agent a temporary inbox.Prompt injection through email: how to protect AI agentsAnyone can email your agent's inbox, so email is attacker-controlled input. How injection works and the defences Emailsify builds in.