I've got a good database of clients who have opted in to receive offers from us but I've never used it, which seems such a waste... Presumably the best thing would be to set up an email newsletter with news and offers, but I don't know how to do this. Do you need special software? Do I need a professional to do it? How do you stop it getting classified as spam (a lot of filters do this when it's sent out to a lot of people at the same time). Has anyone done this before?