Spam "could delay new mobile technologies"
Unsolicited e-mail, or "spam", cost European businesses an estimated two-and-a-quarter-billion euros (£1.5bn) in lost productivity last year, according to the European Commission.
The figure was cited by the European Commissioner with responsibility for information technology, Erkki Liikanen, as he appealed for international co-operation to fight the unwanted, mostly sales-related messages.
European Union (EU) legislation banning unwanted e-mail is due to come into force in November, but given the global nature of the Internet, it is feared it will have little effect.
The scourge of unwanted e-mail is now so serious that it is threatening to stifle the Internet as an effective means of communication.
Mr Liikanen said between a third and one-half of all e-mails sent and received was now spam or junk mail.
If spam is not checked, it is feared it could severely undermine the appeal of mobile-phone-based Internet services, which are about to come onstream in Europe.
Under a new EU directive, it will shortly be an offence to send any unsolicited mail without the recipient's prior consent, but most spam comes from the United States and China and will be outside the law's reach.
In contrast to Europe, the United States is considering a variety of laws which would regulate spam, but essentially allow it unless an individual specifically opts out.
The European Commission readily admits international co-operation is vital.
Today, Mr Likanen offered to host a special summit on the problem at the OECD next year.