"The reason phishing e-mails are so prevalent is due to their success rate," said Carole Theriault, senior security consultant at Sophos, in a statement. "If you receive more than five phishes per day, you're either alert to the dangers or you're likely to have been robbed blind.More details over here.
"With crooks employing more and more devious methods to dupe users, the best advice is to always be wary of unsolicited e-mails, and at all costs avoid parting with confidential information," she added.
One fifth of Internet users receives more than 5 phishing mails a day

Sophos surveyed 600 business users and found that almost 60 percent receives one or more phishing e-mails a day. Twenty two percent even receives five or more daily.