Email Sender MCP Skill

FastMCP server for sending emails via Gmail API.

Quick Start

# Start MCP server
python src/mcp_servers/email_sender.py

# Or via scripts
python scripts/run.py

MCP Tools

1. send_email(to, subject, body, cc, bcc, requires_approval) - Send or queue email
2. send_from_template(template_name, to, variables, requires_approval) - Template-based send
3. archive_email(message_id) - Archive sent email

Production Gotchas ⚠️

Cloud Mode Forces Approval

When FTE_ROLE=cloud, ALL emails are forced to approval workflow regardless of requires_approval flag:

if role == "cloud":
    requires_approval = True  # Always enforced

Recipient Limit (FR-003)

Maximum 5 total recipients (to + cc + bcc combined). Exceeding returns error:

Error: Recipient limit exceeded. Max 5 allowed, got {count}.

Separate Token Files

Sending requires different token than reading:

• token_email.json - For sending (gmail.send scope)
• token.json - For reading (gmail.readonly scope)

Template Subject Required

When using send_from_template, variables MUST include subject:

# ✗ FAILS
send_from_template("welcome.j2", "user@example.com", {"name": "John"})

# ✓ WORKS
send_from_template("welcome.j2", "user@example.com", {"name": "John", "subject": "Welcome!"})

Rate Limit Fail-Safe

When audit log read fails, rate limiting blocks (fail-safe):

except Exception:
    return False  # Block on error, not allow

Rate Limits

Limit	Value
Hourly	10 emails
Daily	100 emails

Tracked via Vault/Logs/email_audit_log.md.

Approval Workflow

Set requires_approval=True to queue email for human review.

Approval files created in Vault/Pending_Approval/:

• Move to Vault/Approved/ to send
• Delete to reject

Configuration

Required in config/:

• credentials.json - Google OAuth credentials
• token_email.json - Gmail send token (separate from read)

Templates directory: src/templates/email/

Environment Variables

FTE_ROLE=local|cloud  # cloud forces approval for all sends

Verification

Run: python scripts/verify.py

Related Skills

• watching-gmail - Read and categorize incoming emails
• digital-fte-orchestrator - Approval workflow processing