mark_email_read · ProtonMail MCP Server MCP: Risk & Policy

WHAT IT DOES

What mark_email_read does on ProtonMail MCP Server

AI agents use mark_email_read 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 mark_email_read needs a policy

Marking emails as read/unread changes email metadata (the read status flag) in a reversible manner. This constitutes a Write operation—data is modified but the action can be undone by marking it unread again. The severity is low because the blast radius of accidental misuse is minimal; it only affects email flags, not content deletion, financial transactions, or code execution.

From the tool's definition Tool description explicitly states it 'Mark[s] an email as read or unread', which modifies email metadata state. This is a reversible modification operation without destructive or financial implications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mark_email_read Rate-limited

mark_email_read 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": {
    "mark_email_read": {
      "limits": [
        {
          "counter": "mark_email_read_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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 mark_email_read

What does the mark_email_read tool do? +

Mark an email as read or unread. 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 mark_email_read? +

Register the ProtonMail MCP Server MCP server in PolicyLayer and add a rule for mark_email_read: 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 mark_email_read? +

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

Can I rate-limit mark_email_read? +

Yes. Add a rate_limit block to the mark_email_read 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 mark_email_read completely? +

Set action: deny in the PolicyLayer policy for mark_email_read. 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 mark_email_read? +

mark_email_read 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.