Somewhere down the line your email address has been 'harvested' by a site ... lots of them about ... could be anything where you have provided your email address. Unfortunately, these lists are then passed on and on to other lists and it's almost impossible to keep ahead of the SPAM ... best advice, get a new email address and only give it to those people/organisations that you really want to have it. Don't transfer your address books directly in case your existing account has been infiltrated. Dump the old account or keep it for anything dodgy you give your email for. It's sometimes a good idea to have two or three separate email accounts for different aspects of your communications ... at least then you compartmentalise the threat from spam, harvesting, viruses etc.