I'd be interested to know if the PDF contained any form of maleware (was my first thought when I read the email), but also if he's got a subscription list, and telling people "Steem Cash" launches on 4th August, what else will he be trying to do on / after 4th August? Will he be contacting people directly about purchasing through him etc etc...
RE: [WARNING: SCAMMER on Steemit] - "Steem Cash" is the latest project of a known con-man