UK IT managers could be spending more than five million working hours, worth more than £140m a year, searching for valid e-mails caught in spam filters, according to a survey commissioned by web-based email management service provider, Mimecast.
Research firm e-Media surveyed more than 100 IT managers and found that 26% checked their e-mail quarantine every day and 12% checked it twice a day.
Using E-Skills figures of 270,000 IT managers in the UK and average hourly rates, and allowing 10 minutes for each check, e-Media said a lack of confidence in the accuracy of spam-detection systems could be costing business 5.85 million working hours worth £140.4m a year.
The figures could be even higher, with the survey showing that 16% of those surveyed checked their e-mail quarantine for "continually" for incorrectly captured messages.
According to the survey, 10% said their business was severely affected by delays in the delivery of e-mails and 7% said important e-mail was incorrectly classified as junk mail on a daily basis.
Peter Bauer, chief executive of Mimecast, blamed the inefficiencies of many anti-spam products on the fact that they use a content-scoring approach to identify spam.
"This approach is flawed because it looks at the actual content of messages and calculates a score based on the type of words and links, but many legitimate e-mails in the legal, pharmaceutical and financial sectors include content associated with spam," said Bauer.
He said more effective e-mail management could be achieved by examining e-mail messages before they reach company e-mail servers and either accepting or rejecting them based on whether they come from a trusted contact or not.