'We couldn't find wave@frontlinethoughts.com on any social networks.'

Simply ask the recipient of the email who it is from i.e. name, company, other email addresses, twitter, facebook, etc. Now you can crowdsource your info with a caveat that the info is not necessarily accurate. The customer that contribute would be more likely to be invested in your product and the ones that do not contribute would be getting SOME information rather than nothing at all.