Following whitelisting of an IP or network via Reputation > Good Senders > Local Good Sender IPs, some messages from the whitelisted IP or network continue to have anti-spam policies applied to them.
Messages which have a Received header containing two different IPs, one which is listed in the Local Good Sender IPs list and one which is not, are not treated as originating from the Local Good Sender IP.
Received: from 192.168.192.1 ([188.8.131.52]) by cs-vlab1.testdomain.local with Microsoft SMTPSVC(6.0.3790.211);
This is a known issue with Messaging Gateway (SMG) 10.6.3 and earlier.
This issue has been addressed with the SMG 10.6.4 release.