Someone sent me an email containing the URL of a site to be reviewed. Entourage "has blocked the following potentially unsafe attachment...", and then overwrites it with "Remove Them Learn More".
I've also just come across this issue, and this link appears to provide the solution. It looks like a pretty convoluted process, and I've not yet tested it, but... it might be worth a go for any users who find this annoying [ie, pretty much everyone].