We are setting up an antiques store and planning on sending out postcards to designers and existing clients (we sold to at shows), but that'll have to be done after the holidays. In the meantime I could email these people, but only some have signed in our guestbook and some have authorized us verbally. I just don't want to SPAM, so we are wondering what's the current practice in these cases. Is a onetime email despicable or not? They would be restricted to the antiques world in our area. What do you think?