ISP for small business

Can anyone offer me some advice (on behalf of a mate), please?

My mate has a small business, with a website and business eMail addresses (through Pipex at the moment).

He gets on average 4000-5000 spam emails a day - I have installed spam filtering on his pc, which gets rid of most of them, but it takes quite a while to process when he boots up in the morning, and if he takes a few days off, it takes hours to process them.

He has just got an XDA, and of course, as the filtering is on the PC, he is getting all the spam when he gets his mail.

Can anyone suggest a suitable ISP which spam filters at the server end, for a small business?

[pedantic]

I would suggest looking here which is a forum specific for business users.

[altis]

It's the domain hosting you need to worry about not the ISP.

I use i-web for the hosting and OfficeMail locally and have managed to set these up to filter out most spam.

First off, and this cuts out most stuff, make sure you only accept real 'to' addresses and blackhole the rest. I do this by forwarding only real ones to a common account. Then make sure spam checking is switched on and then blackhole anything that is definately spam - forward the rest. You can also use filters to blackhole mails that match any pattern that you define eg subject contains viagra.

What's left gets pulled over to OfficeMail where the 'from' address is compared with a whitelist. Anything else gets held in abayance and presented on an internal webpage. Any user in the office can look through theses and accept or refuse as required.

All this still requires some effort but it's cut down the problem enormously.