How to Secure AI Email and Communication Agents

AI email and communication agents — systems that draft, send, and manage emails, Slack messages, or other communications on behalf of users — carry extreme risk because a single unauthorized message can leak confidential data, damage business relationships, or trigger compliance violations. SafeClaw by Authensor secures communication agents with recipient whitelisting, content inspection rules, rate limiting, and mandatory human approval for high-stakes messages. Install with npx @authensor/safeclaw to prevent your email agent from becoming a liability.

The Communication Agent Risk Profile

Email agents are uniquely dangerous because their output leaves your system permanently:

  ┌───────────────────────────────────────────────┐
  │  IRREVERSIBILITY SCALE                         │
  │                                                │
  │  file_write ──────── Can undo (restore backup) │
  │  shell_execute ────── Sometimes reversible      │
  │  email_send ─────────── IRREVERSIBLE           │
  │  public_post ────────── IRREVERSIBLE           │
  │  production_deploy ──── Difficult to reverse    │
  │                                                │
  │  Email/communication = highest irreversibility  │
  └───────────────────────────────────────────────┘

Specific risks include:

• Data exfiltration — Agent emails internal documents to external addresses
• Impersonation — Agent sends messages as the user without their knowledge
• Spam and reputation damage — Agent enters a loop sending hundreds of emails
• Confidentiality breach — Agent includes sensitive context in the message body
• Social engineering amplification — Prompt injection causes the agent to send phishing emails

SafeClaw Policy for Email Agents

# safeclaw-email-agent.yaml
version: "1.0"
agent: email-assistant
rules:
  # === SENDING ===
  - action: email_send
    to:
      domain: "company.com"
    decision: allow
  - action: email_send
    to:
      domain: "trusted-partner.com"
    decision: allow
  - action: email_send
    to:
      domain: "*"
    decision: deny   # Block all external recipients by default

# === CONTENT CONTROLS ===
  - action: email_send
    body_contains:
      - "password"
      - "api_key"
      - "secret"
      - "credential"
      - "ssn"
      - "credit card"
    decision: deny   # Block messages containing sensitive terms

# === ATTACHMENTS ===
  - action: email_attach
    file_path: "reports/public/**"
    decision: allow
  - action: email_attach
    decision: deny   # No arbitrary file attachments

# === RATE LIMITING ===
  - action: email_send
    decision: allow  # (for permitted recipients above)

limits:
  max_emails_per_session: 10
  max_emails_per_hour: 25
  max_recipients_per_email: 5
  on_limit_exceeded: halt_and_notify

# === READING ===
  - action: email_read
    folder: "inbox"
    decision: allow
  - action: email_read
    folder: "sent"
    decision: allow
  - action: email_read
    decision: deny

Recipient Whitelisting: The Critical Control

The most important safety control for email agents is recipient whitelisting. By only allowing messages to specific domains, you prevent:

1. Data exfiltration — The agent cannot email documents to attacker@evil.com
2. Phishing amplification — The agent cannot send messages to arbitrary external addresses
3. Accidental sends — The agent cannot CC the wrong domain

# Strict: only internal recipients

action: email_send
  to:
    domain: "company.com"
  decision: allow

action: email_send
  decision: deny

For agents that must contact external parties, use explicit address whitelisting:

- action: email_send
  to:
    address: "support@vendor.com"
  decision: allow

action: email_send
  to:
    address: "billing@partner.com"
  decision: allow

action: email_send
  decision: deny

Content Inspection

SafeClaw can inspect outgoing message content for sensitive patterns before allowing the send:

content_inspection:
  deny_patterns:
    - "\\b\\d{3}-\\d{2}-\\d{4}\\b"    # SSN format
    - "\\b\\d{16}\\b"                   # Credit card numbers
    - "AKIA[0-9A-Z]{16}"               # AWS keys
    - "-----BEGIN.*KEY-----"            # Private keys
    - "CONFIDENTIAL|DO NOT DISTRIBUTE"  # Classification markers
  on_match: deny_and_alert

Human-in-the-Loop for High-Stakes Messages

For messages that pass policy checks but carry business risk, SafeClaw supports human approval:

rules:
  - action: email_send
    to:
      domain: "company.com"
    cc_count_gt: 10
    decision: require_approval  # Mass internal emails need human review

- action: email_send
    subject_contains: "termination"
    decision: require_approval  # Sensitive topics need human review

Audit Trail for Communications

Every email action — drafts, sends, reads, attachment operations — is logged in SafeClaw's hash-chained audit trail. This is critical for compliance (GDPR, HIPAA) where you must demonstrate that automated communications were authorized and appropriate. SafeClaw has 446 tests, works with Claude and OpenAI, and is MIT-licensed.

Cross-References

• Preventing Agent Email Sending
• Data Exfiltration Prevention
• Human-in-the-Loop Gating
• GDPR AI Agent Compliance