update_domain_signature
Set the per-domain email signature. mode=off disables; mode=default seeds newly-created mailbox identities; mode=enforced overrides per-mailbox signatures on the webmail compose path. Non-off modes require effective HTML after sanitization. Omit signature_html to preserve the current HTML, or pas...
This record as markdown: /tools/trekmail-mcp-server/update-domain-signature.md
What update_domain_signature does on TrekMail MCP Server
AI agents use update_domain_signature to create or update resources in TrekMail MCP Server, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your TrekMail MCP Server environment.
Why update_domain_signature is rated Medium
Modifies domain-wide email signature configuration reversibly; affects email presentation but not data deletion or financial operations.
From the tool's definition set per-domain email signature, mode controls behavior, HTML sanitization applied
Attacks that exploit this kind of access
The rule that runs update_domain_signature safely
PolicyLayer is an MCP gateway: it sits between your AI agents and TrekMail MCP Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For update_domain_signature, this is the rule to start with:
update_domain_signature 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.
The button opens the PolicyLayer dashboard: create your workspace, connect TrekMail MCP Server, apply this rule, and every update_domain_signature call is checked against it from then on.
Questions about update_domain_signature
Set the per-domain email signature. mode=off disables; mode=default seeds newly-created mailbox identities; mode=enforced overrides per-mailbox signatures on the webmail compose path. Non-off modes require effective HTML after sanitization. Omit signature_html to preserve the current HTML, or pass an empty string with mode=off to clear it. Safe HTML up to 65535 characters is accepted; unsafe tags are stripped. It is categorised as a Write tool in the TrekMail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the TrekMail MCP Server MCP server in PolicyLayer and add a rule for update_domain_signature: 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 TrekMail MCP Server. Nothing to install.
update_domain_signature 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 update_domain_signature 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 update_domain_signature. 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.
update_domain_signature is provided by the TrekMail MCP Server MCP server (trekmail/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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