groundmail-mcp@0.29.6
VERIFIED· not startedPublisher claims: "Groundmail MCP server: send and receive email, give agents mailboxes, manage domains, templates, webhooks and suppressions from Claude, Cursor, ChatGPT and other MCP clients" Observed in sandbox: no network, touches nothing outside the project, writes no memory.
Coverage
Not started: dependency install failed; the server itself was not observed.- Tested
- the dependency install step · every file read, file written and host contacted by what ran
- Not tested
- server startup · the tool list · tool behavior
What this means for the label: Verified here covers what ran. The server's tools were not exercised with a real credential, so nothing about their behavior is asserted; the credential summary below says what to do with that.
Before you give it your token
- It will ask for
GROUNDMAIL_API_KEYGROUNDMAIL_CREDENTIALS_ENCRYPTION_KEYGROUNDMAIL_MCP_RESOLVE_SECRETGROUNDMAIL_OAUTH_ISSUERConfiguration, not credentials: GROUNDMAIL_API_URL, GROUNDMAIL_APP_URL, MCP_HTTP_PATH, PROTECTED_RESOURCE_METADATA_PATH- Where it talks to
- groundmail.dev (its own)
- What the honeypot saw
- no credential files read · no network
- What we could not test
- server startup · the tool list · tool behavior
Connect it with a scoped credential, under the guard. It asks for GROUNDMAIL_API_KEY, GROUNDMAIL_CREDENTIALS_ENCRYPTION_KEY, GROUNDMAIL_MCP_RESOLVE_SECRET, GROUNDMAIL_OAUTH_ISSUER and talks to groundmail.dev. Give the credential to the guard, not the server: the value never enters the server's environment and only travels to the host you bind. What the tools do with a real credential was not observed.
Never paste a credential into a chat, a ticket or a report, including ours. How the guard holds it.
Is [email protected] safe to install?
KillerSkills ran it in the KillerSkills honeypot sandbox (2 scenarios; not started: dependency install failed; the server itself was not observed) on 2026-11-11 and scored it 85/100 (Verified). In what ran, nothing we could detect went wrong: no undeclared network egress, no credential reads, no persistent instruction writes. What it does with a real credential was not observed; the static findings and the publisher carry the rest of the score. Summary: no network, touches nothing outside the project, writes no memory.
Behavior trace
Honeypot run · 9 s · 2 scenarios · 0 deviationsStatic findings
| **ChatGPT** | Settings → Apps & Connectors → Create (developer mode) → paste the URL, authentication OAuth |Fix: Keep SKILL.md to visible, descriptive text. Remove comments and encoded text that address the agent.<summary><strong>Cursor with an API key (stdio)</strong></summary> `.cursor/mcp.json`: ```json { "mcpServers": { "groundmail": { "command": "npx", "args": ["-y"Fix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.| **ChatGPT** | Settings → Apps & Connectors → Create (developer mode) → paste the URL, authentication OAuth |Fix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.<summary><strong>Cursor with an API key (local or hosted HTTP)</strong></summary> ```bash npx -y groundmail-mcp --http --port 3000 ``` ```json { "mcpServers": {Fix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.<summary><strong>Claude Code with an API key</strong></summary> ```bash # Hosted, API key claude mcp add --transport http groundmail https://mcp.groundmail.dev/Fix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.…om the dashboard at https://app.groundmail.dev/import, or run the local server (npx -y groundmail-mcp) where the key stays on your machine."; var MCP_TOOLS = [ { …Fix: Pin versions and sources; vendor anything fetched at install time.Cost to the agent
Tokens estimated at four characters each. The tool list is re-read by the agent on every turn, so it is the number to compare between servers that do the same job: ranked across the index.
Known vulnerabilities
No advisories in OSV for groundmail-mcp@0.29.6 as of 3d ago. This is the package itself, not its dependencies.