Sample Azure Policy rule to match the Email pattern

tag-like-email-policy-rule.json

"policyRule": {
  "if": {
    "field": "[[concat('tags[', parameters('tagName'), ']')]",  // For example, 'owner' as the tag name
    "notLike": "*@contoso.com" // To match the corporate email address pattern
    // The 'notLike'operator doesn't support multiple wildcards, so '*.*@contoso.com' won't work if you want to use the pattern like 'Name.Surname@contoso.com'.
  },
  "then": {
    // Some policy effect...
  }
}