Advanced Routing

Enterprise edition adds regex patterns and header-based conditions to MXHook's routing engine.

Regex Recipient Patterns

Match recipients using regular expressions for complex routing logic:

curl -X POST http://localhost:8080/routes \
  -H "Content-Type: application/json" \
  -H "X-API-Key: your-api-key" \
  -d '{
    "domain": "yourdomain.com",
    "recipient_pattern": "^ticket-\\d+@yourdomain.com$",
    "webhook_url": "https://yourapp.com/tickets"
  }'

This matches addresses like ticket-123@yourdomain.com, ticket-9999@yourdomain.com, etc.

Examples

Pattern	Matches
^ticket-\d+@domain.com$	ticket-123@domain.com
^(sales|marketing)@domain.com$	sales@domain.com, marketing@domain.com
^.+-noreply@domain.com$	alerts-noreply@domain.com, billing-noreply@domain.com

Pattern Syntax

MXHook uses Go's regexp package, which implements RE2 syntax. Notable differences from PCRE:

• No backreferences
• No lookahead/lookbehind
• Linear-time matching (no catastrophic backtracking)

Header-Based Conditions

Route emails based on header values. This enables routing decisions based on metadata beyond the recipient:

curl -X POST http://localhost:8080/routes \
  -H "Content-Type: application/json" \
  -H "X-API-Key: your-api-key" \
  -d '{
    "domain": "yourdomain.com",
    "recipient_pattern": "*@yourdomain.com",
    "webhook_url": "https://yourapp.com/high-priority",
    "header_conditions": {
      "X-Priority": "1"
    }
  }'

Use Cases

• Priority routing — route high-priority emails to a faster processing pipeline
• List filtering — route mailing list emails differently based on List-Id
• Source identification — route based on X-Mailer or custom headers
• Auto-reply detection — filter auto-replies using Auto-Submitted header

Evaluation Order

When advanced routing is enabled, routes are evaluated as:

1. Header conditions are checked first (if present)
2. Recipient pattern is matched (exact, wildcard, plus-addressing, or regex)
3. First route where both conditions match wins