mailrust is an MCP server. Claude, ChatGPT, Cursor or your own agent can search and read your mail, sort it, write drafts and replies, work with outreach prospects, manage newsletter subscribers, keep your calendar and tasks, all within the rights you give it.
MCP, the Model Context Protocol, is how AI programs use other systems: the server names its tools, the agent calls them. Every installation has one MCP address:
https://mail.example.com/mcp
Two ways to connect
| Program | How it signs in |
|---|---|
| claude.ai, ChatGPT and other web apps | OAuth: mailrust opens a consent screen where you sign in and choose the rights. See claude.ai and ChatGPT |
| Claude Code, Cursor, your own scripts | An agent key you create in mailrust and paste into the program. See Claude Code, Cursor and others |
Either way the agent appears on your Agents screen, where you change its rights or revoke it.
What an agent may do
Each agent has its own rights, set per area: mail, outreach, newsletters, contacts, calendar, tasks, analytics and deliverability. You choose which mailboxes it sees, whether its emails wait for your approval, how many it may send a day and how long it may work. A new agent can only search and read mail until you give it more. See Rights and approval.
An agent never goes beyond your own access: if you cannot see a mailbox or a campaign, neither can your agent.
Emails wait for you
By default every email an agent writes waits under Agents → Waiting for approval, with its text, until you press Send or Reject. The number of waiting emails shows next to Agents in the side panel.
What the administrator controls
Under Admin → Agents an administrator decides whether agents may connect at all, whether any agent may send without a person's approval, and can revoke any agent on the installation. Every email an agent sends, every change it makes and every approval lands in the audit log with the agent's name.
Protocol
mailrust speaks the MCP version 2026-07-28 and the earlier 2025-11-25, 2025-06-18 and 2025-03-26, over Streamable HTTP. Old and new clients connect to the same address. The full list of tools is in the Tools reference.