Remove an email address from a client
AI agents call remove_from_suppression_list to permanently remove resources in Campaign Monitor MCP — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Suppression lists are used to ensure certain email addresses (e.g., unsubscribes, bounces, complaints) are never contacted. Removing an address from this list bypasses those protections and cannot be easily undone if emails are subsequently sent to that address.
From the tool's definition 'Remove an email address from a client' — removing from a suppression list reverses a suppression, potentially allowing emails to be sent to addresses that were deliberately blocked, which is a significant and potentially irreversible compliance action
Attacks that exploit this kind of access
Remove an email address from a client. It is categorised as a Destructive tool in the Campaign Monitor MCP MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Campaign Monitor MCP server in PolicyLayer and add a rule for remove_from_suppression_list: 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 Campaign Monitor MCP. Nothing to install.
remove_from_suppression_list is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the remove_from_suppression_list 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 remove_from_suppression_list. 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.
remove_from_suppression_list is provided by the Campaign Monitor MCP server (pauliowest/cmon-mcp). 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 →