Chris Drake wrote:
N> So to make effective use of SPF I really need to have my own mail
N> server, which means moving to dsl on a fixed ip.
Running a mail server on DSL might not be a good idea - if your DSL is
DUL or RBL listed (most are) you'll find some stuff you send won't
reach the recipients.
Some are, some aren't. However, a DUL listing will have no effect on your
ability to run a mail server for incoming mail, and you could smarthost the
outgoing mail via the ISP's servers.
SPF is *NOT* an anti-spam technology.
It will not have ANY NOTICEABLE IMPACT on your spam problem EVER.
Actually it does at the moment because a proportion of spam & viruses
(particularly viruses) comes with sender addresses in your own domain and can
be rejected as forgeries. This situation is unlikely to last for long though.
Have you looked at CR technology? Purists hate it because some
bounced spams end up hitting the forged senders addresses, however, it
does eradicate 100% of your spam without any danger that you'll ever
miss and email due to a false positive. Places like mailblocks.com
might be worth checking out. You've just got to figure out how much
money your 9000 spams are costing you, and whether or not their fee is
worth it of course.
I wouldn't use CR (Challenge-Response) for a business mail system as it will
definitely cost you business. The people that dislike CR systems generally do
so with a passion and will not respond to challenges at all. So you'll not get
any mail from them unless you know in advance that they'll be sending you mail
and you whitelist them.
Paul.