can you ask for an email address to one of the sales persons?

You could simply ask them if they have a business card as it most of the time has it on the bottom right corner.

Really? I've never gotten a card with an SA's email address printed on it at LV (though I do know it's on cards for Saks and Tiffany SAs).

But to answer your question SAs do have business email addresses- I have my SA's though I usually prefer to call the boutique and ask for her when I know she's working.