If e-mail is the Internet's killer application, then spam and viruses are doing a good job of destroying e-mail as an effective means of communication.In June 2004, spam accounted for 86.3% of all inbound corporate e-mail scanned by e-mail security tools vendor MessageLabs. The company says it stopped nearly 792 million spam e-mails during last month, translating to 1 out of every 1.16 e-mails being categorized as spam. This spam figure is up dramatically from a year ago, when 38.5% of e-mail was categorized as spam.Indeed, spam volumes have grown steadily over the last four months. MessageLabs data shows that spam rose from representing 52.8% of all e-mail in March to 67.6% in April, 76.1% in May and 86.3% in June.Also in June, MessageLabs stopped 97 million viruses. That figure means that 9.3% of all e-mail - or 1 out of every 10.7 e-mails - contains a virus. The virus figure is also up from June 2003, when 1 in 125 e-mails was infected with a virus.Virus figures have held steady over the last three months. MessageLabs recorded 1 in every 10.58 e-mails was infected in April, 1 in 10.96 e-mails was infected in May and 1 in 10.7 e-mails was infected in June.MessageLabs scans e-mail on behalf of 8,500 customers.