Most aren't willing or able to communicate via email--particularly on sales-related issues. Since anything put in an email can (and will) be used against them, they try to stick to verbal communications.
Several years ago I was told that all outbound messages must go thru some sort of review process to make sure they don't contain any comments / statements which could come back and bite Disney at a later date. Don't know if that's still true or not, but it certainly makes sense.
A seemingly innocuous statement could easily cause them great harm at a later date. Imagine if someone had put this in writing to a potential customer about 10 years ago: "Early-December is a very slow period and our lowest cost time of the year. You'll never have problems booking outside of your Home resort at 7 months."
The DIS doesn't permit posting of corporate email addresses here. I think your best route is to just ask your Guide if he/she is williing to communicate via email. If so, then you'll have the address.