Being a tight arse i was hoping for a free way of doing this but ended up paying a little to get this working. Here's the situation: i'm on BT broadband in the UK and all their dynamic IP addresses are blacklisted automatically. But i want to run a smtp server at home which will spit out emails once a day to users of my beta site: www.planetnomad.com when they request it.
I purchased a Mail Outbound service (from dyndns.org) and Postcast Professional Server - $15 a year and £48 respectively. Postcast allows you to enter a Smtp gateway server which will act as a hop to get your emails out there. Dyndns gives you the server details and once entered you can create emails and send them to your heart's content.
www.planetnomad.com is a google map app. that will send out emails to users notifying them of new information in a specified location. For me, i've got it sending out emails detailing new stories from Reuters news service that occur every day in Europe. To try it yourself just register and set up a favourite view.