Adding PTR domains

Procedure

1. Go to Inbound Protection → Connection Filtering → Reverse DNS Validation.
2. Click the Blocked PTR Domains tab and click Add.
3. On the Add Blocked PTR Domain screen, configure information about the PTR domain from which you want to block messages.
   1. Specify a domain name in one of the following formats:
      • example.com
      • subdomain.example.com
      • *.example.com
        This format matches all the subdomains under the example.com domain, for example, a.example.com, a.b.example.com.
   2. Type a description for the domain.
   3. In the Exception(s) section, specify exceptions to the blocked PTR domain and click Add.
      The domains in the exception list must be subdomains of the blocked PTR domain. Cloud Email Gateway Protection does not block messages from these subdomains.

      To delete an exception, select the exception item and click Delete.
   4. Click Save.
      The blocked PTR domain appears in the blocked PTR domain list.