Why some addresses masquerading do not work properly in Symantec Brightmail Gateway 9.0
The localpart of an e-mail address must be case sensitive.
The product is working as designed. You should create a corresponding address masquerading to match the localpart case of the e-mail address.
-You have created an address masquerading using the Protocols -> Address Masquerading page in Symantec Brightmail Gateway 9