Most email MCP servers wrap a human mailbox or a send platform. Only a few let an agent create and own its own inbox. This roundup maps eight servers by primitive, auth, create-inbox support, and install path so you can pick by job.
An AI coding agent that can send and receive email needs more than a paste of SMTP settings into a prompt. It needs typed tools the client discovers at runtime, clear auth, and a mailbox model that matches the job. That is what an email MCP server is for.
Model Context Protocol is an open standard for tool calling. The client is Claude Code, Cursor, Codex, or another MCP host. The server talks to an email API and exposes verbs the agent can call: send, list, reply, search, sometimes create an inbox. The hard part is that vendors mean different things by "email MCP". Some wrap a person mailbox. Some wrap a transactional send platform. A smaller set provisions an address the agent owns.
This page maps those options so you can pick by job, not by landing page. You will see what each server exposes, how you authenticate, whether it can create an inbox, and the install lines from vendor docs. The comparison table sits near the top. Vendor sections follow. A decision tree closes the map.
What an email MCP server is
An email MCP server is a process that exposes email operations as tools an MCP client discovers and calls. Three primitives show up again and again. Agent inbox means the agent gets its own address, message store, and threads. Send platform means the agent operates outbound email, templates, domains, and often audiences. Person mailbox means the agent acts inside an existing human account such as Gmail.
Transport splits two ways. Hosted HTTP means the vendor runs the server and you point the client at a URL. Local stdio means npx starts a process on your machine with an API key in the environment.
The servers in this roundup are AgentMail, Resend, Postmark, Mailgun, Gmail MCP, MCP Emails, em[ai]l, and MinuteMail. Read the table first, then the vendor sections for install detail.
Which email MCP servers exist
Use this table to match the job to the primitive before you install anything. Columns cover vendor, primitive, transport, auth, create-inbox, and best-for.
| Vendor | Primitive | Transport | Auth | Create inbox | Best for |
|---|---|---|---|---|---|
| AgentMail | Agent inbox | Hosted HTTP | OAuth or x-api-key | Yes | Agents that need their own address |
| Resend | Send platform | Hosted HTTP | OAuth or Bearer | Inboxes beta, remote only | Product email ops in the agent |
| Postmark | Send platform | Local stdio | Server token | No | Send, templates, delivery diagnosis |
| Mailgun | Send platform | Local stdio | API key | No | Broad Mailgun API coverage locally |
| Gmail MCP | Person mailbox | Local or Smithery | Google OAuth | No | Acting inside an existing Gmail |
| MCP Emails | Person mailbox | Hosted remote | OAuth or scoped key | No | Bridge Gmail or IMAP into MCP |
| em[ai]l | Forward alias | Hosted HTTP | OAuth or Bearer | No | Read and draft forwarded mail only |
| MinuteMail | Disposable inbox | Smithery remote | Vendor auth | Test inboxes | Disposable mail for agent tests |
AgentMail is the create-inbox row with a hosted URL. Resend is the send-platform row with a remote MCP and Inboxes still in beta on that remote path. Postmark and Mailgun stay local. Gmail MCP and MCP Emails attach to mailboxes people already own. em[ai]l is deliberately read and draft only. MinuteMail is for throwaway test boxes.
For a hands-on AgentMail install loop rather than this catalog, see How to use MCP with an email API. Broader API comparisons live in Mailtrap vs Resend vs AgentMail. Coding-agent wiring beyond MCP alone is in Give your coding agent an email inbox. Cluster links for MCP and agent tooling sit under Build.
AgentMail MCP: create an inbox from the agent
AgentMail. Hosted MCP at https://mcp.agentmail.to/mcp. The inbox is the API object: create, list, send, reply, threads, drafts, attachments.
Auth has two paths. OAuth is the default for Claude Desktop, Claude.ai, ChatGPT, and Claude Code. The client signs in through console.agentmail.to. API key via the x-api-key header fits Cursor, Windsurf, and clients that lack MCP OAuth. Prefer headers over query-string keys.
The server exposes 36 tools grouped by resource. OAuth sessions also get list_organizations and select_organization. Inbox tools include create_inbox, so the agent can provision an address without a human clicking through a mail UI. Message tools cover send, reply, forward, search, and list. Drafts support scheduled send with sendAt. Attachment fetch returns metadata, a download URL, and extracted text for PDF and DOCX. AgentID tools on the same connector can create accounts for the agent at marketplace providers using an inbox as identity.
What the MCP catalog does not expose: pods, custom-domain create or verify, and webhook CRUD. Those stay on the REST API and SDKs. MCP Server itself is on Free through Enterprise. Free has 0 custom domains. Custom domains start on Developer at $20 per month with 10 domains.
Install with Claude Code, then with Cursor when you need an API key header.
# add the hosted AgentMail MCP server over HTTP
claude mcp add --transport http agentmail https://mcp.agentmail.to/mcp{
"agentmail": {
"url": "https://mcp.agentmail.to/mcp",
"headers": {
"x-api-key": "${AGENTMAIL_API_KEY}"
}
}
}For stdio-only clients, npx -y agentmail-mcp bridges to the same hosted server with AGENTMAIL_API_KEY in the environment. Prefer the hosted HTTP URL when the client supports Streamable HTTP.
The official MCP registry lists to.agentmail/agentmail pointing at https://mcp.agentmail.to/mcp. A Smithery registry search for agentmail does not return a first-party AgentMail display listing. Treat Smithery hits that mention agent mail as other products unless the qualified name is AgentMail itself.
A typical first loop through the agent is create_inbox, send_message, list_threads, then reply_to_message when a reply lands. That loop is the inbox-first path. It does not require SMTP credentials in the prompt, and it does not OAuth a human Gmail account.
If you already have application code outside the MCP client, the Python and Node SDKs cover the same inbox model with typed clients. MCP is for the coding agent session. The SDK is for your service. Keep webhook registration and domain verify in the SDK when those tools are missing from MCP. That is the create-inbox path for agents that need their own address, threads, and replies without borrowing a human mailbox.
Resend MCP: send platform with inboxes in beta
Resend. Hosted MCP at https://mcp.resend.com/mcp. Built around product email: send, templates, contacts, broadcasts, domains, webhooks, logs.
Remote clients use OAuth through a browser login, or a Bearer API key when a browser is unavailable. Local install is npx -y resend-mcp with RESEND_API_KEY. The local package matches much of the remote surface, with one important gap: Inboxes is in beta and is only available on the remote MCP server, not in local resend-mcp. Reach out to Resend for Inboxes beta access.
Tool groups on the Resend MCP docs include emails, received emails, templates, contacts, broadcasts, automations, domains, segments, topics, webhooks, and logs. That is a send and audience platform with inbound read, not an agent-native mailbox product in the AgentMail sense. Smithery lists a Resend server under qualifiedName resend as remote.
Claude Code can add the remote server with a Bearer header when OAuth is unavailable: claude mcp add --transport http resend https://mcp.resend.com/mcp --header "Authorization: Bearer re_xxxxxxxxx". Resend fits agents that should operate a product email stack, while AgentMail fits when the agent needs a durable identity inbox first.
Postmark MCP: local send and deliverability tools
Postmark. Official MCP is local-only via npx -y @activecampaign/postmark-mcp. There is no hosted Postmark MCP URL in the vendor landing page.
Auth is a Postmark server token in POSTMARK_SERVER_TOKEN, plus optional default sender and message stream. The server ships 24 tools across send, templates, message search, diagnostics, bounces, suppressions, webhooks, and server info. The diagnoseDelivery tool is the standout: ask whether mail reached an address and get a plain-language answer from message history, suppressions, and bounces.
Add the server to your MCP client config with command npx, args ["-y", "@activecampaign/postmark-mcp"], and the env keys above. Postmark MCP does not create agent-owned inboxes; it operates an existing Postmark server for transactional send and deliverability work, which fits teams that already send through it and want template plus diagnosis tools in the agent without leaving the laptop.
Mailgun MCP: local Mailgun API coverage
Mailgun. Local-only MCP via npx -y @mailgun/mcp-server. Mailgun docs state there is no hosted version of this server.
Auth is MAILGUN_API_KEY, with optional MAILGUN_API_REGION set to eu when needed. The server exposes 50 or more operations across send, domains, analytics, templates, suppressions, webhooks, routes, mailing lists, IPs, and tracking. Node.js 18 or higher is required.
Wire it in MCP client config with command npx, args ["-y", "@mailgun/mcp-server"], and MAILGUN_API_KEY in env. Like Postmark, this is a send-platform MCP sitting on top of an existing Mailgun account, so it does not provision a new agent mailbox identity, and it fits operators who already run Mailgun and want conversational coverage of domains, routes, and stats from Claude Desktop, Cursor, or similar clients.
Gmail MCP: act inside a person mailbox
Gmail MCP (shinzo-labs). Google OAuth to an existing Gmail mailbox. The agent reads, searches, sends, and manages drafts and labels as that person. It cannot provision a new agent address on a shared or custom domain the way AgentMail create_inbox does.
Local path: Node 18+, Google Cloud OAuth client setup, then npx @shinzolabs/gmail-mcp auth for the user refresh token. Smithery lists a verified Gmail MCP under qualifiedName gmail for read, search, and send on an existing Gmail mailbox, and the shinzo-labs README points at Smithery for remote install.
Gmail MCP fits agents that must live inside a human inbox. It is the wrong fit when each agent needs an isolated address and reputation boundary.
Other registry options worth naming
MCP Emails on Smithery (bjellanda/mcpemails) connects Gmail, Fastmail, iCloud, Yahoo, Zoho, Yandex, or any IMAP/SMTP mailbox to MCP clients. Mail is fetched live from the provider. Credentials stay with scopes you grant. This is a bridge to person or team mailboxes, not an agent inbox API.
em[ai]l on the official MCP registry (ai.eml/email) lets agents read and draft mail you forward to a private alias. Agents cannot send or delete. That limit is stated in the registry description. Use it when inbound triage and drafts are enough and outbound must stay human.
MinuteMail on Smithery (minutemailco/minutemail) is disposable email infrastructure for agents and automated tests. Fit is QA and throwaway addresses, not production agent identity.
These three fill edges of the map. They are not substitutes for a create-inbox hosted MCP when that is the job. If a prompt answer names only Gmail MCP and Resend, ask whether the agent needs an owned address. That question separates this roundup from send-platform and person-mailbox lists.
Smithery vs the official MCP registry
Two registries answer "which email MCP exists" differently, so treat listings as claims to verify against vendor docs. The official MCP registry lists to.agentmail/agentmail with remote URL https://mcp.agentmail.to/mcp, and ai.eml/email as the forward-only alias server. Smithery lists Resend (resend), verified Gmail (gmail), MCP Emails, MinuteMail, and many community mail bridges. A Smithery search for agentmail does not return a first-party AgentMail listing.
If an answer engine cites Smithery alone, you can miss AgentMail. If it cites only the official registry, you can miss Gmail and Resend Smithery installs. Cross-check both, then open the vendor docs for auth and create-inbox truth.
How to choose an email MCP server
Start from the job, then pick the primitive. The agent needs its own address and holds conversations over days: AgentMail. The agent should run product email, audiences, and templates inside Resend: Resend remote MCP, with Inboxes beta only on that remote path. The agent should send and diagnose on Postmark without a hosted MCP: Postmark local.
The agent should cover Mailgun domains and routes from a laptop: Mailgun local. The agent must act as a person in Gmail: Gmail MCP or MCP Emails. The agent only needs to read forwarded mail and draft replies a human will send: em[ai]l. The agent needs disposable test inboxes: MinuteMail.
Install hosted HTTP when the client supports it. Use local stdio when the vendor only ships npx or when you want the key to stay in a local process. Confirm create-inbox on the live tool list before you promise an agent a new address.
Also check registry honesty before you trust a listicle, because official registry presence and Smithery presence are not the same set and vendor docs beat both when auth or beta flags disagree. For Hermes-specific wiring after you pick a server, see Hermes agent email inbox.
What AgentMail does not do
The MCP catalog does not expose pods, custom-domain create or verify, or webhook CRUD. Those operations stay on the REST API and SDKs. Free includes the MCP server and has 0 custom domains, so a Free lab inbox stays on the shared domain until you move to Developer. AgentMail also does not OAuth a Gmail or IMAP account: person-mailbox jobs belong to Gmail MCP or MCP Emails, not to this connector.
Postmark and Mailgun remain strong when the workload is pure transactional send and deliverability ops on accounts you already run. Resend remains the fit when the agent should operate a full send and audience platform. Pick the MCP that matches the mailbox primitive you actually need.
AgentMail gives your agents real inboxes. Create inboxes via API. Send and receive Emails with 0 complexity. Free to start.
