Inbound spam volume continues to increase significantly, with no signs of abating. (e.g. in 2005, an average of 30 billion spam email messages were sent daily; by 2007, that average had quadrupled to 120 billion daily spam messages.)
The incentive driving this global spam industry is profit. Despite its catastrophic impact on business productivity and network performance, and despite even high-profile prosecutions of spammers, spam still works.
Spam is constantly getting more sophisticated because spammers are typically technically savvy and early adopters of innovative technology.
Outbound threats are also becoming a top priority, based upon fears of regulatory non-compliance and the leakage of sensitive intellectual property or confidential information.
Data leaks are not limited to malicious acts; most confidential data leaks are likely due to employee carelessness. Additionally, as much as 25% of computers on the Internet are estimated to be infected with botnets or zombies, which can infect corporate mail servers and generate outbound attacks.