Data Loss Prevention

Has anyone implemented Symantec DLP and integrated it with Proofpoint cloud? I currently have a Proofpoint server that sees inbound and outbound e-mail traffic and block spam; however those are currently physical servers. I am on an initiative to move the Proofpoint to the cloud but am unsure how emails will be crawled using the Symantec DLP tool to block unauthorized types of emails going out.  Also does anyone know if the DLP can also capture inbound traffic to block spam email?  Thank you in advance.

I might want to split your question into two parts:

(A) Outgoing Content Filtering (in other words DLP) for emails traffic coming from Cloud based Proofpoint Solution:

 - Many organisations now (mostly starting 2015) are trying to adapt to this new architecture/environment (cloud); as pioneers have known to adapt different strategies. The common ones without getting too much into CASB & other methods are:

 - A1 (Strategy One): Backhaul all traffic back to premise for DLP inspection, post which release it to WAN again

 - A2 (Strategy Two): Explore with your Symantec Sales Team, the roadmap/feasibility on making "Symantec DLP Cloud Service for Email" work with Forcepoint which at present officially supports Microsoft Office 365, Gmail and few others.

(B) DLP blocking SPAM

 - If you have some sort of a team assembled already for some of your other security tools/IDS/patch management/etc. which is good at pearl, then is some potential in the DLP Flexresponse component however it would be an uphill task to me, with nobody else in the race. In other words, DLP is not a SPAM blocking tool. It is an expert solution designed for content filtering leaving the company premises.