Posted by Virus Bulletin on Mar 18, 2012
Catch rates significantly lower than in previous months.
In the latest VBSpam comparative test, 20 solutions achieved a VBSpam award, but the majority displayed significantly lower spam catch rates than in other recent tests.
Overall, products' spam catch rates were significantly lower than in previous months, with many products seeing their rates of missed spam doubled. This is a worrying trend: many reports have indicated that global spam levels have dropped significantly in the past year. But if the performance of spam filters also drops, there is little net gain for the end-user, who will still regularly see their inbox filled with spam.
The drop in spam catch rates was most significant at the perimeter, suggesting that spammers are doing a better job at avoiding blacklists. It is possible that spammers are increasingly using legitimate services to send their messages, which poses new challenges for anti-spam companies.
There was good news for one product this month, though - Libra Esva blocked 99.97% of all spam messages without blocking any legitimate mail, and as such was the only product to obtain the new 'VBSpam+' award (to qualify for the VBSpam+ award, products must achieve a spam catch rate that is higher than 99.5% and a zero false positive rate).