postfleet

Secure email infrastructure for AI agents.

CommunityOnlineAPI key requiredGlobalFreeCan modify data

What it can do

  • List Mailboxes: List the mailboxes you can use, newest first, each with its id and email address. Call this when you need a mailbox_id for any other tool, or to check whether you already have a mailbo
  • Create Mailbox: Create a NEW email mailbox this agent owns. Call this when list_mailboxes shows you have no suitable mailbox yet — mailboxes persist across sessions, so creating a second one for the s
  • List Domains: List the account's custom sending domains with their id, name, and verification status. Call this when you want to create a mailbox on a custom domain (pass the id of a verified domain a

What data it sees

Do you need an account

An API key from the service settings is required

Secure email infrastructure for AI agents. Every inbound message is verified, sanitized, and screened for prompt injection before your agent reads it — hidden HTML, zero-width characters, and decode-then-apply payloads are stripped or fail closed — then delivered as typed JSON. Outbound send is idempotent, with optional human approval on consequential replies.

How to connect

How to connect postfleet to Claude

The server address to paste into Claude settings:

https://postfleet--scottiefoster.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect postfleet to ChatGPT

The server address to paste into ChatGPT settings:

https://postfleet--scottiefoster.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect postfleet to Cursor

The server address to paste into Cursor settings:

https://postfleet--scottiefoster.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (14)

Raw names from tools/list. Only developers need these.

list_mailboxesList the mailboxes you can use, newest first, each with its id and email address. Call this when you need a mailbox_id for any other tool, or to check whether you already have a mailbox before creating one — it is usually the first call in a workflow. Returns every mailbox on the account, or just your own if your API key is scoped to a single mailbox. An empty list means you have none yet — use create_mailbox.
create_mailboxCreate a NEW email mailbox this agent owns. Call this when list_mailboxes shows you have no suitable mailbox yet — mailboxes persist across sessions, so creating a second one for the same purpose strands mail in the first. Returns a working address immediately. Optional slug personalizes the address (agent-<slug>@...). To create the mailbox on a custom domain instead of the shared one (<slug>@yourdomain.com), pass a domain_id from list_domains — the domain must be verified.
list_domainsList the account's custom sending domains with their id, name, and verification status. Call this when you want to create a mailbox on a custom domain (pass the id of a verified domain as create_mailbox's domain_id), or to check whether a domain has finished verifying. Only status "verified" domains can host mailboxes; an empty list means only the shared platform domain is available.
send_emailSend a new email from one of your mailboxes. Call this when starting a NEW conversation; to answer an email you received, use reply_email instead (it threads correctly). Pass a client_id (any unique string you make up) and reuse the SAME client_id if you retry after an error — that guarantees the email is sent at most once. If the mailbox requires human approval, the send is queued as a draft and returns {draft_id, status:"pending_approval"} instead of a message id — that is NOT a failure and must NOT be retried; the email goes out once a human approves it (check with list_drafts).
reply_emailReply to an email you received. Call this when answering an existing message — recipient, subject, and conversation threading are derived automatically from the original. Pass a client_id (any unique string you make up) and reuse the SAME client_id if you retry after an error — that guarantees the reply is sent at most once. If the mailbox requires human approval, the reply is queued as a draft and returns {draft_id, status:"pending_approval"} instead of a message id — that is NOT a failure and must NOT be retried; it is sent once a human approves it (check with list_drafts).
list_inboxList recent messages in a mailbox, newest first, with comprehension status per message. Call this when checking what has arrived; use read_email for full content and extracted data.
read_emailRead one email in full: cleaned body, sanitization report (screened against known hidden-content patterns), classification, and data extracted to the mailbox schema. Call this when you need the content or extraction of a specific message.
wait_for_emailBlock until a matching email arrives in a mailbox (or time out). Call this when you just sent an email and need the reply, or are expecting an inbound message — instead of polling list_inbox yourself. Returns the full message on match, or {timed_out:true}.
create_draftPrepare an email as a draft without sending it. Call this when you want to stage a message for later or for a human to review before it goes out — send it afterward with send_draft. Same fields as send_email, or omit to/subject and pass reply_to_message_id to draft a threaded reply. Returns the draft id with status "draft".
list_draftsList the open drafts in a mailbox (status draft, pending_approval, or sending), newest first. Call this when you need to see messages you have staged or that are queued waiting on human approval, e.g. after a send returned status "pending_approval".
get_draftRead one draft in full by its id: recipient, subject, body text, and current status. Call this when you need the content of a specific draft — e.g. to review what is queued for approval after list_drafts, or before editing it with update_draft.
update_draftEdit the to, subject, or text of a draft that has not been sent yet — omitted fields keep their current value. Call this when a draft needs changes, e.g. a human declined to approve it and you are revising it. The reply target cannot be changed (create a new draft to reply to a different message), and a draft that is already sending or sent can no longer be edited.
send_draftSend a draft you prepared, by its id. Call this when a staged draft is ready to go out. If the mailbox requires human approval, this returns 202 {draft_id, status:"pending_approval"} — the draft is queued for a human to approve, which is NOT a failure and must NOT be retried; it is sent once approved. Otherwise it sends immediately and returns the message id.
delete_draftDiscard a draft by its id so it will never be sent. Call this when a staged or pending-approval message should be withdrawn — e.g. it is no longer needed or was created by mistake. A draft that is already sending or sent cannot be deleted.