
"Instant messaging, joined by free and low-cost VoIP calling, will result in slower email growth, especially among teens and young adults."
IDC projects that 2007 email levels will reach 97bn messages, totalling 5 exabytes of data.
Spam is expected to be largest single category of that pool with 40bn messages. Unsolicited email also for the first time ever will exceed person-to-person email messages, the firm predicted.