I'm not sure what is going on. When a sender sends an email to my customer how is on SBS 2008/Exchange 2007 the email does not get to the SBS box and the sender recieves this error back
" the following message to _______ is undeliverable. The reason for the problem: Other mail system problem. 550-'5.7.1 Message rejected as spam by content filtering
I belive due to some words it is blocked.
Send a simple test mail and check.