Skip to content

3LT Letter Mail

by 3lgrouptechnology.com · remote · no sign-in to list tools · v1.0.0 · published by com.3lgrouptechnology

Give AI assistants hands: send real USPS letters via MCP.

Final · 4Changes · 2
CompareRegistry entry

7 tools: 4 do something that can't be undone, 2 change things and 1 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http 3lt-letter-mail https://3lgrouptechnology.com/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

7 tools

Can't be undone 4Claude Code: ask
  • draft_letterCreate a letter DRAFT: verifies the recipient address with PostGrid, screens content, and returns a price quote.No findings

    Why it is in this group

    • The description's first verb is "create": a word for a change.
    • The input addresses people (input.to): what it sends cannot be taken back.
    Description, as the server wrote it
    Create a letter DRAFT: verifies the recipient address with PostGrid, screens content, and returns a price quote. This NEVER mails anything. Pass EITHER html (letter body as an HTML string) OR pdf_path (path to a PDF file on the server). PDF text is extracted for screening; if extraction fails the draft is kept but flagged needs_review.
  • request_sendRequest that a draft be mailed.No findings

    Why it is in this group

    • The name "request_send" says "request": a word for a change.
    • The name "request_send" also says "send": a word for sending, and what is sent cannot be taken back.
    Description, as the server wrote it
    Request that a draft be mailed. approval-tier keys: creates a PENDING request and returns a one-tap Allow/Deny approval_url for the human. Nothing is mailed until Allow. on_command keys: may auto-send inside guardrails (spend caps, content screening, anomaly detection); anything outside them stays PENDING.
  • send_faxTransmit an APPROVED fax via Phaxio.No findings

    Why it is in this group

    • The name "send_fax" says "send": a word for sending, and what is sent cannot be taken back.
    Description, as the server wrote it
    Transmit an APPROVED fax via Phaxio. Refuses drafts that were never approved and faxes that were already sent — a fax can be transmitted exactly once.
  • send_statusCheck a send request: status (PENDING/SENT/REJECTED/FAILED), the key's trust tier and tier decision, approval state (+approval_url while pending), and billing state (Stripe charge …No findings

    Why it is in this group

    • The name "send_status" says "send": a word for sending, and what is sent cannot be taken back.
    Description, as the server wrote it
    Check a send request: status (PENDING/SENT/REJECTED/FAILED), the key's trust tier and tier decision, approval state (+approval_url while pending), and billing state (Stripe charge id when billed).
Changes things 2Claude Code: ask
  • approve_faxApprove a fax DRAFT so it can be transmitted.No findings

    Why it is in this group

    • The name "approve_fax" says "approve": a word for a change.
    Description, as the server wrote it
    Approve a fax DRAFT so it can be transmitted. The content is re-screened at approval time. Only the key that created the fax can approve it. Nothing is transmitted by this call — send_fax does that.
  • create_fax_draftCreate a fax DRAFT: validates the recipient number, counts the PDF's pages, screens its text, and returns a price quote (Phaxio per-page cost x pages + the flat $1.00 service fee).No findings

    Why it is in this group

    • The name "create_fax_draft" says "create": a word for a change.
    Description, as the server wrote it
    Create a fax DRAFT: validates the recipient number, counts the PDF's pages, screens its text, and returns a price quote (Phaxio per-page cost x pages + the flat $1.00 service fee). This NEVER transmits anything — call approve_fax, then send_fax.
Only reads 1Claude Code: allow
  • get_fax_statusCheck a fax: lifecycle status (DRAFT/APPROVED/SENT/FAILED), page count, quote, and — once sent — the live delivery status from Phaxio.No findings

    Why it is in this group

    • The name "get_fax_status" says "get": a word for reading.
    Description, as the server wrote it
    Check a fax: lifecycle status (DRAFT/APPROVED/SENT/FAILED), page count, quote, and — once sent — the live delivery status from Phaxio.

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http 3lt-letter-mail https://3lgrouptechnology.com/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__3lt-letter-mail__get_fax_status"
    ],
    "ask": [
      "mcp__3lt-letter-mail__draft_letter",
      "mcp__3lt-letter-mail__request_send",
      "mcp__3lt-letter-mail__send_status",
      "mcp__3lt-letter-mail__create_fax_draft",
      "mcp__3lt-letter-mail__approve_fax",
      "mcp__3lt-letter-mail__send_fax"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as 3lt-letter-mail. Review it before you use it.