buy a 1U, put it in a colo center (should cost you about $50/month) and proxy all your outbound mail from there. stop thinking of broadband as anything other than a lastmile protocol between your house and your own piece of the internet core.
This is darn good advice. And to expand on it further, it is time to stop thinking of Simple Mail Transport Protocol (SMTP) as the way for everybody to send email. For some strange reason we have managed to develop two protocols for end users to use in talking to their mail service provider (POP and IMAP) but neither of them allow the end user to send email. One would think that an authenticated session with an email service provider would be the natural protocol to use for injecting end user email into the system. Imagine a world in which only ISPs run SMTP servers which only talk directly to other servers with which they have an offline relationship. A world in which everybody hands over their email to an ISP for onward delivery in order to get it into the system. A world in which it is virtually impossible to send anonymous or forged email without the cooperation of an ISP. To get to this world we have to stop trying to fix the SPAM problem. Instead, we have to fix the email architecture problems which have created the environment in which SPAM can thrive. A new architecture might not prevent SPAM but if it makes spamming hard to do and has rate limits that make it very hard to do high volumes of unauthorized email then most people will not care about the small volume of SPAM. We need to start with an Email Service Consortium with a code of email server practices in which the larger ISPs agree to stop accepting SMTP connections from anyone who is not in the consortium or a customer. This will get everyone implementing a set of well-known and consistent controls. We need to add email sending capability to both POP and IMAP so that eventually we can all block port 25 entirely from broadband/dialup edges. And we need to reinstate the use of SMTP relays in order for smaller ISPs to have access to the core of the email system. --Michael Dillon