Poll an inbox until an email arrives. Returns the email once received. Times out after the specified duration.
Part of the Email server.
Free to start. No card required.
AI agents invoke wait_for_email to trigger processes or run actions in Email. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.
wait_for_email can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.
Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.
{
"version": "1",
"default": "deny",
"tools": {
"wait_for_email": {
"limits": [
{
"counter": "wait_for_email_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}See the full Email policy for all 7 tools.
These attack patterns abuse exactly the kind of access wait_for_email gives an agent. Each links to the full case and the policy that stops it:
Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Poll an inbox until an email arrives. Returns the email once received. Times out after the specified duration.. It is categorised as a Execute tool in the Email MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Email MCP server in PolicyLayer and add a rule for wait_for_email: 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 Email. Nothing to install.
wait_for_email is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the wait_for_email 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 wait_for_email. 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.
wait_for_email is provided by the Email MCP server (@useblip/email). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Email tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.