I was logged in as Admin on my smartermail ( 1gig VPS ) I checked out the stats, and it showed that smartermail has blocked over 5000 emails / 24 hours. I have 8 domains running on this, is this pretty normal? I am using spam assasin, spamhaus, spamcop, reverse DNS. If any of them come back bad, I block the connection.

That's not a surprising or unusual number of SPAM to be rejected. A lot of factors go into the amount of SPAM an address may receive and with 8 different domains with (I'm assuming) multiple users per domain it can be quite high.

For instance- I have an address that I don't post anywhere online or use for signing up for anything and it receives on average over 1,000 SPAM messages a day. An address that I use as a SPAM magnet when I need to sign up for something online, or post an address somewhere, receives 3 times that.

There are a few things you can do to reduce the amount of incoming SPAM. The first would be to make sure any email addresses that are included on a website (such as a contact form) are obfuscated. Another good practice is to encourage users to use a free email address when signing up for anything online.

I would also generally recommend getting postini. This takes the filtering burdon from your server and puts it on their server. Postini does a better job at filtering then most IPBased ways and has less false positives.