Retrieve the full detail for a single message by ID.
AI agents call mailosaur_messages_get_by_id to retrieve information from Mailosaur MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves message data from Mailosaur's testing service based on a message ID. It performs a read-only operation with no side effects, reversible modifications, code execution, data destruction, or financial impact. The only risk is potential unauthorized access to test email/SMS messages, which is mitigated by access control at the Mailosaur service level.
From the tool's definition Tool name 'mailosaur_messages_get_by_id' and description 'Retrieve the full detail for a single message by ID' indicate a data retrieval operation with no modification or deletion of data.
Attacks that exploit this kind of access
Retrieve the full detail for a single message by ID. It is categorised as a Read tool in the Mailosaur MCP MCP Server, which means it retrieves data without modifying state.
Register the Mailosaur MCP server in PolicyLayer and add a rule for mailosaur_messages_get_by_id: 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 Mailosaur MCP. Nothing to install.
mailosaur_messages_get_by_id 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 mailosaur_messages_get_by_id 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 mailosaur_messages_get_by_id. 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.
mailosaur_messages_get_by_id is provided by the Mailosaur MCP server (mrnewdelhi/mailosaur-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 →