send_draft · ProtonMail MCP Server MCP: Risk & Policy

WHAT IT DOES

What send_draft does on ProtonMail MCP Server

AI agents use send_draft to create or update resources in ProtonMail MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ProtonMail MCP Server environment.

WHY IT NEEDS A POLICY

Why send_draft needs a policy

Although send_draft modifies the Drafts folder by removing the draft, its primary function is to initiate outbound email transmission to recipients outside the system. This is a write operation in the sense that it creates/transmits a message that cannot easily be retracted and can have significant consequences (e.g., sending sensitive information, impersonation, financial requests).

From the tool's definition Tool description states 'Send an existing draft via SMTP' — this performs an irreversible action that commits data (email message) to external recipients, modifying the state of communications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_draft Rate-limited

send_draft stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "send_draft": {
      "limits": [
        {
          "counter": "send_draft_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches ProtonMail MCP Server, so you can run agents against it safely.

FAQ

Questions about send_draft

What does the send_draft tool do? +

Send an existing draft via SMTP and remove it from Drafts. It is categorised as a Write tool in the ProtonMail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on send_draft? +

Register the ProtonMail MCP Server MCP server in PolicyLayer and add a rule for send_draft: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches ProtonMail MCP Server. Nothing to install.

What risk level is send_draft? +

send_draft is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit send_draft? +

Yes. Add a rate_limit block to the send_draft rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block send_draft completely? +

Set action: deny in the PolicyLayer policy for send_draft. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides send_draft? +

send_draft is provided by the ProtonMail MCP Server MCP server (ronamosa/protonmail-pro-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.