More than half the e-mails sent throughout the world are spam - unsolicited messages, often containing pornographic material or dodgy financial offers.
In America, it's reckoned that the average office worker spends an hour every week deleting spam - that's more time than they spend in the toilet.
Now the government is to introduce new electronic privacy regulations which aim to stop spam messages - but only if they come from Europe.
Breakfast spoke to to Tony Harbon, whose company, Cleaview Systems, supplies anti-spam software - and Miles Mendoza from Radio Two's Steve Wright programme.
Miles Mendoza's golden rules
To avoid spam, says Miles - never buy anything from a spammer, however much of a good deal may appear to be on offer.
And never reply to an invitation to unsubscribe from a spam mailing list. If you do, you're telling the spammer that your e-mail address is active, so you'll get even more junk mail.
Tips from business Breakfast
Research shows that activities most likely to reveal your email address to spammers are posting to newsgroups or message boards, entering AOL chat rooms, and signing up for online sweepstakes and lotteries.
Online shopping and subscribing to email newsletters are lower risk, but not risk-free.
We suggest you always read a site's privacy policy, and use a secondary email address for signing up to any message boards, posting to news groups or online shopping.
Hotmail accounts seem to attract a lot of spam. You might want to choose a more obscure UK based provider or consider a 'disposable email' service like Sneakemail.
A free download called Mailwasher enables you to preview emails before you download them to your PC.
You can scan a list of messages waiting for you and decide whether to delete them, bounce them back to the sender, or download them to your inbox.
If you want to take your personal fight against spam further, a tool called Spamcop will help you identify the real address a spam message has been sent from, and contact the spammer's service provider to get their account shut down.