When reviewing the mail logs you see a number of errors indicating a problem with the utils.lua script but message processing appears to be otherwise working as expected.
maillog ------- (err) ecelerity: [5276] scriptlet-00410: smg error: Symantec/Brightmail/mta/lib/scriptlets/smg/utils.lua:25: attempt to index local 's' (a boolean value) (err) ecelerity: [5276] scriptlet-00327: validate_data error: Symantec/Brightmail/mta/lib/scriptlets/smg/utils.lua:25: attempt to index local 's' (a boolean value)
Some message From headers were being incorrectly processed for Sender Authentication
This issue has been addressed with the SMG 10.7.3 release.