Nine out of 10 emails are spam

Nine out of 10 emails coming to your inbox are spam, according to security vendor Symantec.

According to the company's MessageLabs Intelligence Report, spam had increased by 5.1 per cent since April, reaching 90.4 per cent.

This is the highest level of spam since September 2007, and is a big increase from only two months ago in March, where spam "only" made up 75.7 per cent of all emails.

Symantec said that the increase in spam for May was due to email messages coming into inboxes that only consisted of a subject line and a hyperlink pointing to a profile on a social network.

It said that the profiles had likely been created using random names and automated CAPTCHA-breaking tools, and were sent using valid webmail providers.

"As spam levels continue to increase, we are seeing existing attack techniques combine and morph into one," said MessageLabs Intelligence senior analyst Paul Wood in a statement.

"In 2008 CAPTCHA-breaking, social networking spam and the use of webmail for spamming all became popular tactics. Today, the bad guys are using the three together as a triple threat to heighten the effectiveness of their spamming."

Interestingly, the report also showed that location determined when a user would receive spam. People in the US saw spam peak at 9am to 10am, while Europeans saw a steady stream of spam during the day.

"These patterns suggest that spammers are more active during the US working day," said Wood.

"This could be because most active spammers are based in the US, or because this is when the spammers' largest target audience is online and likely to respond."