How can I use custom rules?

Key Concepts:

• • You can view a sample JSON response by performing a single email verification.
• • Use dot.notation to reference fields (e.g., syntax.domain).
• • Conditions support partial matches by default — if the value contains the string, it matches.
• • Use regex: prefix for regex-based matching (e.g., "input":"regex:[.]+").
• • Combine conditions using AND and OR for complex logic trees.
• • Actions also use dot.notation to override values (e.g., misc.is_disposable:true).

Formatting:

Fields are referenced with dot.notation. For example, if your response includes:

{"misc":{"is_free":false}}

You would reference this as misc.is_free in your conditions or actions.

Basic Condition:

Mark all free email providers as invalid:

Condition:
{"misc.is_free":true}

Action:
{"is_reachable":"invalid"}

If misc.is_free is true, is_reachable becomes invalid.

Logical Operators (AND):

Consider role-based and deliverable emails as safe:

Condition:
{"logic":"AND","conditions":[
  {"misc.is_role_account":true},
  {"smtp.is_deliverable":true}
]}

Action:
{"is_reachable":"safe"}

Both conditions must be true. If it’s role-based and deliverable, the email is marked safe.

Logical Operators (OR):

From invalid to safe if domain or username matches certain criteria:

Condition:
{"logic":"AND","conditions":[
  {"is_reachable":"invalid"},
  {"logic":"OR","conditions":[
   {"syntax.domain":"acmeservices.com"},
   {"syntax.username":"sales"}
  ]}
]}

Action:
{"is_reachable":"safe"}

If the email is invalid AND (domain contains "acmeservices.com" OR username contains "sales"), it's marked as safe.

Partial Matching:

Mark any email address containing "yahoo.com" as invalid:

Condition:
{"syntax.domain":"yahoo.com"}

Action:
{"is_reachable":"invalid"}

Regex Matching:

Flag Gmail-style aliases or Emailnator patterns (e.g. [email protected]) as invalid:

Condition:
{"logic":"AND","conditions":[
  {"misc.is_free":true},
  {"syntax.username":"regex:([.].*){2,}|\\+"}
]}

Action:
{"is_reachable": "invalid", "misc.is_disposable": "true"}

This marks free email addresses that contain either 2+ dots in the username or a + symbol as invalid.

Fast Check compatibility:

Custom rules run on both Deep Verification and Fast Check integrations. When a rule fires during a Fast Check, the result is overridden before the response is returned to the visitor, and the dashboard results page shows a “custom rule” indicator next to the status.

Because Fast Check does not perform an SMTP handshake, smtp.* fields are not populated. Only the following fields are available as rule conditions for Fast Check:

• • is_reachable
• • misc.is_disposable
• • misc.is_role_account
• • misc.is_free
• • misc.is_relay
• • syntax.domain
• • syntax.username
• • syntax.is_valid_syntax

Conditions referencing smtp.* fields will not match during a Fast Check and the rule will be skipped.