You have a spam email that was not blocked by the Symantec.cloud AntiSpam service and you want to check if the sender is whitelisted on your end.
Check the email headers of the received email and look for any entry as below:
X-SpamWhitelisted: IP whitelist
X-SpamWhitelisted: domain whitelist
X-SpamWhitelisted: IP whitelist means that the sending server IP of the email is in your Approved Senders List. To know the sending IP of the email, check for the X-Originating-IP entry in the headers.
X-SpamWhitelisted: domain whitelist means that either the domain or the email address of the email is in your Approved Senders List. To know the sender address or domain of the email, check for the X-Env-Sender entry in the headers.
If you want the emails to not bypass Anti-spam scanning, remove these entries (IP, email, or domain) from your Approved Senders List. Follow the steps below: