Fastmail (jordonh19) MCP Server
@jordonh19/fastmail-mcp-server
npm
v1.3.0
Source verified
Published by jordonh18 — publish provenance cryptographically ties this package to that repository. That is proof of origin, not an official vendor package.
MCP server for Fastmail — enables AI assistants to read, search, send, and manage emails, calendars, and contacts via the JMAP protocol
The grade answers one question — how safe is this server for you to adopt — so it is computed in two auditable stages. Nothing below is an opinion or an LLM's guess; every line is a real term the deterministic engine applied, and the same input always yields the same number.
1. Threat score — 100 − 0 = 100. What the published surface and source actually contain:
The deterministic scan raised no scored threat in the surface it inspected — the threat score stayed at 100. Capability observations and advisory notes are recorded but never lower it.
2. Client adoption risk — 100 − 3 = 97. Three small, subtract-only factors that reflect your risk in adopting it — a clean scan proves less on a powerful, unverified or barely-inspectable package, so the grade says so plainly:
| Points | Adoption-risk factor |
|---|---|
| −3 | capability blast radius (moderate) — client exposure if the model is manipulated |
Capability observations and info notes are shown under Findings but never scored.
Open any row's finding below for the file, line and evidence behind a deduction.
Findings 1
medium Untrusted input can drive an external actionMTC-FLOW-005
Untrusted-input tools ([mark_mailbox_read, search_emails, get_unread_emails, get_email_attachments, download_attachment]) co-exist with external-action tools ([send_email, forward_email]). A prompt injection could cause unwanted external actions, though no direct sensitive-data leak path was found.
Evidence: untrusted [mark_mailbox_read, search_emails, get_unread_emails, get_email_attachments, download_attachment] → sinks [send_email, forward_email]
Fix: Require confirmation for state-changing/egress actions triggered after processing untrusted content.
Location: flow mark_mailbox_read → send_email
Tools 47
Each tool and what it can reach — statically extracted from the published source.
download_attachmentingests untrusted inputforward_emailnetwork egressget_email_attachmentsingests untrusted inputget_unread_emailsingests untrusted inputmark_mailbox_readingests untrusted inputsearch_emailsingests untrusted inputsend_emailnetwork egressadd_labelsno sensitive capabilityarchive_emailno sensitive capabilitybulk_add_labelsno sensitive capability
Show 37 more tools ↓
bulk_email_actionno sensitive capabilitybulk_remove_labelsno sensitive capabilitycheck_function_availabilityno sensitive capabilitycreate_calendar_eventno sensitive capabilitycreate_contactno sensitive capabilitycreate_draftno sensitive capabilitycreate_mailboxno sensitive capabilitydelete_calendar_eventno sensitive capabilitydelete_contactno sensitive capabilitydelete_emailno sensitive capabilitydelete_mailboxno sensitive capabilityget_account_summaryno sensitive capabilityget_calendar_eventno sensitive capabilityget_calendar_eventsno sensitive capabilityget_contactno sensitive capabilityget_emailno sensitive capabilityget_email_headersno sensitive capabilityget_identitiesno sensitive capabilityget_latest_emailsno sensitive capabilityget_mailbox_emailsno sensitive capabilityget_mailbox_statsno sensitive capabilityget_threadno sensitive capabilitylist_address_booksno sensitive capabilitylist_calendarsno sensitive capabilitylist_mailboxesno sensitive capabilitymove_emailno sensitive capabilityone_click_unsubscribeno sensitive capabilityremove_labelsno sensitive capabilityrename_mailboxno sensitive capabilityreply_emailno sensitive capabilitysearch_contactsno sensitive capabilitysend_draftno sensitive capabilitysuggest_replyno sensitive capabilitysummarize_emailno sensitive capabilityupdate_calendar_eventno sensitive capabilityupdate_contactno sensitive capabilityupdate_email_flagsno sensitive capability
Toxic flows 1
Cross-tool combinations that form a data-exfiltration primitive (untrusted input → sensitive source → external sink).
What this scan could not see
- Tools were statically extracted from the published source (47 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".
Versions 1
Scan history per published version. The engine is deterministic — the same version always yields the same score, so a changed score means the package itself changed.
| Version | Score | Findings | Engine | Scanned |
|---|---|---|---|---|
v1.3.0 latest |
A 97/100 | 1 | 1.13.0 | 2026-09-07 |
Embed this score
Show this server's live Trust Score in your README, docs or website. The badge is served straight from the registry and updates automatically after every rescan — no API key needed. It links back to this page, so anyone who sees the grade can also read the findings behind it instead of taking a number on faith.
Verify this score yourself
The score above is reproducible: the same package version always yields the same result. Run it locally or over the free API — no account, no LLM, fully deterministic.
npx mcptrustchecker scan @jordonh19/fastmail-mcp-server --onlineOther implementations of Fastmail 3
Independent packages implementing the same tool, scanned with the same engine. Compare all 4 side by side →
MCP server for Fastmail - read, search, and send emails via Claude
🚀 Professional MCP Server for Fastmail email management using JMAP API - Integrates seamlessly with Claude Desktop and other AI assistants
Security scan results for the Fastmail (npm) MCP server.
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