The # 1 thing I tell my custoemrs about why they should leverage Network Prevent for Email instead of the SMG for DLP is the ppolicies written and defined within the DLP system can be more granular both from a type (EDM, IDM, VML, DCM) and the responses can be more granular as well.
Also putting the policy in DLP means that I don't have to duplicate the policy in SMG. So I change the DLP SSN policy for an exception, I may also have to create that exception within SMG which could cause consistency issues.
Symantec has built a FlexResponse Plugin that allows the release of quarantine from the SMG within the DLP console as well. Network PRevent for Email changes the mail header, SMG reads the new mail header and quarantines the email. The incident reviewer then can release that email without aslo having to have access to the SMG. It works really well.
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