CC on Sales Insight emails

I think the Outlook Plugin will do this.

Marketo+SFDC will record the SI email as an Activity on the lead record, so there isn't really a reason to CC yourself.
 

Depending on your goal, you might find subscribing to emails being delivered, opened, or clicked from within Sales Insight will accomplish a similar thing.  I've found the best approach is to spend ten minutes with each sales rep to plan how they can use Sales Insight and set up subscriptions like this.

Thanks Josh and Steven. We've got a couple reps who, on occasion, like to forward a previous email to a prospect. I guess it shows this isn't their first attempt. Not every time though, so I think a subscription would make for too much noise, and unfortunately we are on Google mail.