This article outlines the process that should be followed to test whether the IP DNS Blocklist Anti-Spam filter is properly configured and filtering spam as expected.
Testing IP DNS Blocklist Blocklist functionality is done by sending an inbound test email that is purposely composed in such a way that they will be blocked by the filter.
For this purpose, you will require:
- An SMTP client (such as KMail or Microsoft Outlook) connected to your SMTP server or Exchange environment.
- Administrative access to a local DNS server for the creation of the test DNS records.
- MailEssentials configured to use this local DNS for name resolution.
Follow the below procedure to test the IP DNS Blocklist Anti-Spam filter.
Go to your DNS server configuration.
Create new Forward Lookup Zone gfitest.com
Inside gfitest.com create an A record for 188.8.131.52
Run nslookup to check that the name resolution works
In the configuration console, add gfitest.com to the IP DNS Blocklist
- Using KMail or any other suitable SMTP client, send a test email from an external sender. Use the localhost mail server.
Navigate to GFI MailEssentials > Dashboard and open the Logs tab. Locate the test email you sent which should be blocked with a Scan Result of Blocked [IP DNS] as shown below:
- Note: If the Scan Result shows a different Anti-Spam filter, this means IP DNS Blocklist was configured with a lower priority and you may temporarily disable that filter or alternatively adjust the priority by going to GFI MailEssentials > Anti-Spam > Filter Priority
- Further information can be obtained by checking the debug logs as described in Determining why the IP DNS Blocklist Filter Blocked or Allowed a Message.