Email is required?

Is the email field required for RedHen contacts? It seems me #1955022: No validation errors when the email field is required and left blank, it wasn't always required. I have 400+ contacts without email address. I can import these contacts width feeds module, but after that I can't modify them, while email field is required. Can you provide a switch for this feature?

/redhen/modules/redhen_fields/redhen_fields.module: 308.

<?php
      // At least one email is required.
      if (empty($emails)) {
        $errors[$field['field_name']][$langcode][0][] = array(
          'error' => 'redhen_fields_invalid_email',
          'message' => t('At least one email is required.'),
          'delta' => 0,
        );
      }
?>