Mailcaduceus

☤MailCaduceus

☤MailCaduceus is a shippable skill for enterprise-grade alias/domain control on top of a single Microsoft 365 mailbox and Cloudflare DNS zone.

Innovation Summary

This skill makes one mailbox + one domain behave like an enterprise email control plane by coordinating:

• Entra/Graph authorization
• Exchange transport + alias lifecycle
• Cloudflare DNS/auth posture

That means plug-and-play lane creation, verification, and optimization without mailbox sprawl.

What It Does

• Bootstraps Microsoft Graph + Exchange app permissions with one interactive sign-in.
• Audits credential posture across Graph, Exchange RBAC, and Cloudflare token scope.
• Optimizes root-domain mail posture (SPF, MX, DMARC) with safe defaults.
• Provisions reply-capable or no-reply alias lanes under subdomains.
• Verifies lane readiness (accepted domain, alias attach, Graph state, DNS profile).
• Stores operation outputs atomically for resumable state and operator visibility.

Hard Rules

• Never send group emails from one operation.
• Never send one message to multiple recipients at once.
• Treat no-reply lanes as intentional non-receiving identities (no MX + SPF -all profile).
• Delete defaults are reply-safe: aliases are retired with fallback continuity unless explicitly hard-removed.

Quick Start

# 1) Copy strict credential templates
cp {baseDir}/credentials/entra.txt.template {baseDir}/credentials/entra.txt
cp {baseDir}/credentials/cloudflare.txt.template {baseDir}/credentials/cloudflare.txt

# 2) Edit values in both .txt files

# 3) Run ☤MailCaduceus (autoloads credentials/*.txt)
{baseDir}/scripts/mail-caduceus.sh \
  --organization-domain "northorizon.ca"

Dry Run First

{baseDir}/scripts/mail-caduceus.sh \
  --tenant-id "<entra-tenant-id>" \
  --client-id "<entra-app-client-id>" \
  --organization-domain "northorizon.ca" \
  --mailbox "john@northorizon.ca" \
  --dry-run

Lane Provisioning

# Reply-capable lane
python3 {baseDir}/scripts/email_alias_fabric_ops.py provision-lane \
  --mailbox "john@northorizon.ca" \
  --local "support" \
  --domain "support-reply.northorizon.ca" \
  --send-to "edge0100@icloud.com"

# No-reply lane
python3 {baseDir}/scripts/email_alias_fabric_ops.py provision-lane \
  --mailbox "john@northorizon.ca" \
  --local "support" \
  --domain "support-noreply.northorizon.ca" \
  --no-reply

Retire Lane With Reply Fallback (Recommended)

# Keeps reply continuity by default (fallback mailbox defaults to --mailbox)
python3 {baseDir}/scripts/email_alias_fabric_ops.py retire-lane \
  --mailbox "john@northorizon.ca" \
  --alias-email "support@support-reply.northorizon.ca"

# Explicitly move fallback replies to another mailbox
python3 {baseDir}/scripts/email_alias_fabric_ops.py retire-lane \
  --mailbox "john@northorizon.ca" \
  --alias-email "support@support-reply.northorizon.ca" \
  --fallback-mailbox "inbox@northorizon.ca"

Hard-delete (no fallback continuity):

python3 {baseDir}/scripts/email_alias_fabric_ops.py control-json --ops-json \
  '{"action":"alias.remove","mailbox":"john@northorizon.ca","email":"support@support-reply.northorizon.ca","preserve_reply":false}'

Important:

• Fallback continuity requires the alias domain to remain routable (accepted domain + inbound DNS/MX where applicable).
• If you remove the domain plane itself, replies to that old address will still fail.

Verify Lane

python3 {baseDir}/scripts/email_alias_fabric_ops.py verify-lane \
  --mailbox "john@northorizon.ca" \
  --alias-email "support@support-reply.northorizon.ca" \
  --domain "support-reply.northorizon.ca"

Sandbox Smoke Test

bash {baseDir}/scripts/mail-caduceus-sandbox-smoke.sh

Credentials and Scope Notes

• Strict autoload format:
  • File names: credentials/entra.txt, credentials/cloudflare.txt
  • First non-empty line must be: MAIL_CADUCEUS_CREDENTIALS_V1
  • Remaining lines must be strict KEY=VALUE pairs (no unsupported keys)
  • Templates are included in this skill folder as *.txt.template
• mail-caduceus-bootstrap.ps1.txt is a publish-safe PowerShell source template.
• At runtime, mail-caduceus.sh materializes it into a temporary .ps1 file and executes it.
• Override paths with:
  • MAIL_CADUCEUS_BOOTSTRAP_SCRIPT
  • MAIL_CADUCEUS_FABRIC_SCRIPT
  • MAIL_CADUCEUS_ENV_FILE
  • MAIL_CADUCEUS_INTEL_DIR
  • MAIL_CADUCEUS_CREDENTIALS_DIR
  • MAIL_CADUCEUS_ALLOW_EXTERNAL_SCRIPT_RESOLUTION (default: disabled)

Delete behavior toggles:

• EMAIL_ALIAS_FABRIC_DELETE_PRESERVE_REPLY_DEFAULT=true|false (default: true)
• EMAIL_ALIAS_FABRIC_FALLBACK_MAILBOX=<mailbox@domain> (optional default fallback target)

Persistence toggles:

• --persist-env enables writing non-secret runtime keys to ENV_FILE.
• --persist-secrets enables writing secret values to ENV_FILE (opt-in only).
• Default mode is non-persistent: no .env writes.

Sign-In Model (Important)

• First-time bootstrap (permission grants/admin consent/Exchange RBAC):
  • Interactive PowerShell sign-in is typically required.
• Steady-state operations after bootstrap is complete:
  • Fully headless is supported with ENTRA_CLIENT_SECRET and --skip-m365-bootstrap.
• Recommended production flow:
  • Perform one admin bootstrap once, then run headless for daily operations.

Security Posture (v1.0.0)

• External script resolution is scope-locked by default.
• Credential autodiscovery is scope-locked to this skill directory unless explicitly overridden.
• Bootstrap artifacts redact generated client-secret values before writing state JSON.
• Intel/state output files are written with restrictive permissions (700 dir, 600 files where supported).

Benefits

• One mailbox can run many clean identity lanes safely.
• Domain and alias lifecycle can be automated end-to-end.
• Full state awareness reduces operator guesswork.
• Useful for support, sales, outreach, and transactional messaging with explicit no-reply/reply modes.
• Built for personalized, high-volume outreach with controllable identity variables (display name, alias, subdomain).
• Reduces spam-risk behavior by enforcing single-recipient operations and lane-specific posture.

Outcome

☤MailCaduceus provides Fortune-500-style email operations from a lightweight stack:

• one domain
• one mailbox
• one bootstrap command
• full lifecycle control