Validate an email address to check if it exists and is deliverable. Costs $0.01 per validation.
AI agents call validate_email to retrieve information from Unosend MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and validates email address information without creating, modifying, deleting, or executing operations. It is purely informational. While there is a cost associated with its use, the tool does not move money or commit financial obligations on behalf of the user — it is consumption-based API metering, which is distinct from Financial category (payments, refunds, trades, subscriptions initiated by…
From the tool's definition Tool performs validation check on email addresses with no modification or side effects beyond a query operation. Description states it 'checks if it exists and is deliverable' — a read-only verification.
Attacks that exploit this kind of access
Validate an email address to check if it exists and is deliverable. Costs $0.01 per validation. It is categorised as a Read tool in the Unosend MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Unosend MCP Server MCP server in PolicyLayer and add a rule for validate_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 Unosend MCP Server. Nothing to install.
validate_email is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the validate_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 validate_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.
validate_email is provided by the Unosend MCP Server MCP server (unosend/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →