Few observers have a better view of that ocean of exchanging gossip called E-mail than Mark Sunner. The chief technology officer of E-mail management company MessageLabs, Sunner oversees a network that processes 4.5 million letters each day. Servers operated and maintained by MessageLabs manage mail delivery and routing for a number of companies, including Bank of England and Condé Nast Publications. In fact, all of MessageLabs’ customers are corporations whose daily E-mail output and inflow has soared with the growth of the Web. “E-mail usage has increased massively in the last couple of years,” he says. Indeed, MessageLabs estimates that it has gone from 10 a day per employee as recently as two years ago to more like 20 or 30 now.

 The implications for Corporate America are equally huge. According to E-mail researcher and consultant David Ferris, companies can expect the volume of E-mail coursing through their servers to grow 60% to 80% in 2002. And as individual messages grow in size - they’re now more likely to contain memory - companies could end up paying 100% to 150% more just this year on systems to store and manage those messages. That’s why tech consultancy Radicati Group expects demand for soft ware that manages E-mail, such as Microsoft Outlook and Lotus Notes, to grow from $2.6 billion in sales today to $4.4 billion by 2005. Too much of this money will be spent in controlling pure junk. About 20% of the E-mail MessageLabs manages is unwanted, according to Sunner - who adds that about 1.25% of all the E-mail his company moves contains useless attachments. Already, the cost of handling spam（垃圾邮件）is estimated at $8.6 billion worldwide, according to a 2001 European Union study. And the barrage of pornographic spam has made some companies worried that employees might sue on grounds of disturbance arising from exposure to unwanted unpleasantness.

The first sentence of this passage “Few observers have a better view of that ocean of exchanging gossip called E-mail than Mark Sunner” most probably means ____.