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Proton Mail (unofficial)

io.github.sethbang/proton-mail-mcp·v1.0.2·Email

Unofficial Proton Mail MCP — send, read, search & organize email over SMTP and IMAP

In-path gate · all MCP tools

Using Proton Mail (unofficial) in Claude, Cursor, Gemini CLI, Cline, or Zed?

MCP tool contracts can change remotely with no version bump. The mcpindex gate pins each contract and HOLDs the call when it drifts-before your agent acts. Zero credentials. This is not the package install for this server itself (use Install this server for that).

Install the mcpindex gate (one command)

Rewrites your MCP host config so each server launches behind the gate. Inspect first: curl -fsSL https://mcpindex.ai/install.sh | less

curl -fsSL https://mcpindex.ai/install.sh | sh
Trust verdict · v1 advisory · method
REVIEWstatus: PARTIALfresh until 2026-08-05 09:03 UTC
screened 2026-07-06tier: scannedgranularity: description-levelsource: registry

Semantic screen found no manipulation pattern in the description. Conformance probe not yet run.

mcpindex.integrity.descriptionpassINFO

evidenceDeclared capabilities, no hidden instructionsvia static_description

Limits of this verdict
  • - Semantic screen only - the deterministic conformance probe has not run on this server
  • - Confidence is reported but not yet calibrated (v1)
  • - Screen reads the tool description, not the live behavior
  • - advisory
  • - registry description only no input schema
  • - screen model 8b

Semantic screen: an LLM judge reads the tool description for hidden instructions (status PARTIAL). A pass means the description is not lying, not that the tool is safe: a high-capability tool with an honest description still warrants caution. The deterministic conformance probe has not been run on this server yet, so the screen here is semantic-only. Posture: advisory. Confidences are reported but not yet calibrated (calibrated=false at v1). Full verdict history is not shown on this page.

Own this server? Screen its description →

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A live verdict badge for your README or listing. It reflects the current screen, links back here, and updates when the verdict does.

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Environment variables
PROTONMAIL_USERNAME
required

Your Proton Mail email address

PROTONMAIL_PASSWORD
requiredsecret

Your Proton Mail SMTP password (not your login password; generate one in Proton settings)

PROTONMAIL_HOST

SMTP host

PROTONMAIL_PORT

SMTP port

PROTONMAIL_SECURE

Use TLS for SMTP (true for port 465)

IMAP_HOST

Proton Mail Bridge IMAP host (required for read/search tools)

IMAP_PORT

Proton Mail Bridge IMAP port

IMAP_SECURE

Use TLS for IMAP

IMAP_USERNAME

Proton Mail Bridge username (falls back to PROTONMAIL_USERNAME)

IMAP_PASSWORD
secret

Proton Mail Bridge password (falls back to PROTONMAIL_PASSWORD)

READONLY

Disable all mutating tools (send, move, delete, flags, labels, bulk ops, folder/label management)

RESTRICT_OUTBOUND_TO_SELF

Refuse live sends to any recipient other than PROTONMAIL_USERNAME (for throwaway/QA accounts)

ALLOW_FILE_DOWNLOAD_DIR

Allowlist directory enabling download_attachment.saveTo; when unset, attachments return as inline base64

ALLOW_EMPTY_FOLDER

Register the empty_folder tool (not recommended)

DEBUG

Enable verbose logging to stderr

MCP quality score · maturity, not trust · methodology
freshness
24
completeness
20
installability
25
documentation
15
stability
10
Alternatives in Email