Sadly I have the same problem. But I also notice that Fiverr usually marks these messages as spam. I have been informed by friends on Fiverr that this is normal for new profiles. They have also assured me that after a while these spam messages will stop, and you will get real messages. In the meantime I respond to each message as if it is a real potential customer and emphasize that I only work through Fiverr. Wishing you success.