"Zip-of-death" describes a subterfuge designed to bring down a network by overwhelming the antivirus software and/or network traffic checking security applications.

Using special techniques, a hacker can compress a file down to as little as 500 KB, that, when decompressed, may reach 15 GB or more in size. Another version of the exploit involves compressing such a large number of files, that, when decompressed, it can crash the system.

ScanMail allows you to set limits on the size, as well as the number of files it will extract from a compressed archive. When the limit is reached, ScanMail stops decompressing and takes the action specified for files outside of the scan restriction criteria.