ModelsAtlas
Explore
Atlas / MCP servers / amotivv / Protonmail

ProtonmailSAFE

mcp/amotivv/protonmail
MCP server by amotivv · mcp · modelcontextprotocol · protonmail · Audited 2026-10-08
⚑ Report / re-scanSource ↗

This MCP server provides email sending functionality using Protonmail's SMTP service. It allows both Claude Desktop and Cline VSCode extension to send emails on your behalf using your Protonmail credentials.

Verdict
SAFE
Grade
B
Trust score
89 /100
Exposed tools
1 0r · 1w · 0d
Transport
stdio
License
MIT
Stars
50
01

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

This MCP server is provided by amotivv, inc., the creators of Memory Box.

[](https://opensource.org/licenses/MIT)

This MCP server provides email sending functionality using Protonmail's SMTP service. It allows both Claude Desktop and Cline VSCode extension to send emails on your behalf using your Protonmail credentials.

Compatibility

This MCP server is compatible with:

  • Claude Desktop App: The standalone desktop application for Claude
  • Cline VSCode Extension: The Claude extension for Visual Studio Code

The same implementation works across both platforms since they both use the Model Context Protocol (MCP) standard.

Features

  • Send emails to one or multiple recipients
  • Support for CC and BCC recipients
  • Support for both plain text and HTML email content
  • Comprehensive error handling and logging

Configuration

The server requires the following environment variables to be set in the MCP settings files for both Claude Desktop and Cline:

Claude Desktop Configuration

Located at: /Users/your-username/Library/Application Support/Claude/claude_desktop_config.json

Cline VSCode Extension Configuration

Located at: /Users/your-username/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json

Both configuration files require the following environment variables:

  • PROTONMAIL_USERNAME: Your Protonmail email address
  • PROTONMAIL_PASSWORD: Your Protonmail SMTP password (not your regular login password)
  • PROTONMAIL_HOST: SMTP server hostname (default: smtp.protonmail.ch)
  • PROTONMAIL_PORT: SMTP server p
Read from source at commit 20cd946a7223OBSERVED · 2026-10-08
02

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.

claude-code
claude mcp add protonmail-mcp --env PROTONMAIL_PASSWORD=${PROTONMAIL_PASSWORD} -- npx -y [email protected]
claude-desktop
{
  "mcpServers": {
    "protonmail-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "[email protected]"
      ],
      "env": {
        "PROTONMAIL_PASSWORD": "${PROTONMAIL_PASSWORD}"
      }
    }
  }
}
03

Exposed tools (1)

0 read · 1 write · 0 destructive.

ToolRiskDescription
send_emailwriteSend an email using Protonmail SMTP
04

Trust audit

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

LayerWhat it checksResult
L0Provenance & inventoryPASS
L1Static analysis of the codePASS
L2Instruction surface (what it tells the agent)PASS
L3Class-specific surfacePASS
L4Behavioural (sandbox)SKIPPED

What the source does

Filesystem
none-observed
Network
none-observed
Shell
none-observed
Dependencies
not all pinned
Secrets in source
none-found

Findings (2)

LOWSupply chain · supply.unpinned · CWE-829, CWE-1357
package.json
@types/nodemailer, nodemailer, @types/node, typescript
Why it matters. 4 dependency range(s) float
Fix. pin exact versions or ship a lockfile
LOWPrompt injection · prompt.transfer_instruction · CWE-94, CWE-1427
README.md:15
This MCP server provides email sending functionality using Protonmail's SMTP service. It allows both Claude Desktop and Cline VSCode extension to send emails on your behalf using your Protonmail crede
Why it matters. an instruction to move sensitive data to an outside destination
Fix. remove; a skill never needs the user's secrets off the machine

Gates applied: no_behavioural_pass.

Audited 2026-10-08 · audit v0.4.1 · source sha 20cd946a7223full audit observations/trust-audit/mcp-server/amotivv__protonmail.json · Report an issue / request a re-scan
05

Audit history

Every audit this server has had. A grade with a past is a grade somebody is still checking.

DateSourceVerdictGradeScoreChange
2026-10-0820cd946a7223SAFEB89first audit
06

Questions

What is the Protonmail MCP server?

This MCP server provides email sending functionality using Protonmail's SMTP service. It allows both Claude Desktop and Cline VSCode extension to send emails on your behalf using your Protonmail credentials.

What tools does Protonmail expose?

1 in total: 0 read-only, 1 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.

Is Protonmail safe to connect to an agent?

The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B.

What credentials does Protonmail need?

It reads PROTONMAIL_PASSWORD from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.

How does Protonmail run?

It speaks stdio, so it runs as a local process your client starts. It is published on npm as protonmail-mcp at 0.1.0.

How current is this page?

The grade is for one exact copy of the source (20cd946a7223), read on 2026-10-08. The repository is watched and re-audited when it changes.

Advertisement