Built in spam filters SBS2008

Question

I have an sbs 2008 server with exchange 2007, its running the MS spam filters which picks up the spam fine, however a lot of senders cannot send email to the recipients of the sbs2008 server until they have been emailed first and then that only applies to that one recipient (some form of aggregated white list).

I have tried to track the messages using the built in tools on exchange 2007 but I am not having much joy!

Any ideas?

Answer 1

Just from this info it's not easy to troubleshoot. You can read here for specific information on each of the anti-spam filters.

My advice is to increase the SCL level and see if the problematic users will start sending without problems. After that you can tweak the other filters for better protection.