AI agents use markMultipleAsUnread to create or update resources in Mail MCP Tool — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mail MCP Tool environment.
This tool modifies email state (read/unread flags) across multiple messages, which is a reversible write operation. It does not delete data (not Destructive), execute arbitrary code (not Execute), or move money (not Financial). The impact is limited to email metadata changes that can be easily undone, making it low severity.
From the tool's definition Tool name 'markMultipleAsUnread' indicates modification of email read/unread status. Server description states the tool enables 'email operations' including handling emails.
Documented attack patterns abuse exactly the kind of access markMultipleAsUnread gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mail MCP Tool, and nothing reaches the server without passing your rules. This is the rule we recommend for markMultipleAsUnread:
{
"version": "1",
"default": "deny",
"tools": {
"markMultipleAsUnread": {
"limits": [
{
"counter": "markmultipleasunread_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}markMultipleAsUnread 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.
Free to start. No card required.
markMultipleAsUnread. It is categorised as a Write tool in the Mail MCP Tool MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mail MCP Tool MCP server in PolicyLayer and add a rule for markMultipleAsUnread: 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 Mail MCP Tool. Nothing to install.
markMultipleAsUnread is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the markMultipleAsUnread 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.
Set action: deny in the PolicyLayer policy for markMultipleAsUnread. 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.
markMultipleAsUnread is provided by the Mail MCP Tool MCP server (shuakami/mcp-mail). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 17 Mail MCP Tool tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
17 Mail MCP Tool tools catalogued and risk-classified — across an index of 42,500+ MCP servers.