Adding in my 2p's worth of advice here as well. The big thing I think is your IP. Even if it is 'static', if you are running the MTA from your house, your IP wi

Adding in my 2p's worth of advice here as well. The big thing I think is your IP. Even if it is 'static', if you are running the MTA from your house, your IP will be marked as residential, and probably also still 'dynamic' (just made sticky by your ISP to your Router/Modem). The best way to give your outgoing mail 'authority' is to relay it through a smarthost. Some ISPs offer this - All my outgoing mail from the Exchange server in my Garage routes through my ISPs smarthost - it's the only way I can be sure that the big webmail hosts (hotmail/outlook, gmail, yahoo) actually get the mails. If I try to route direct, the mails get blocked.