August is the worst month for spam

Spam can account for up to 85 per cent of all email traffic in August, according to email filtering company Email Systems.

The company claims that the spam percentage hit 90 on six separate days in August, reaching its peak at 92.59 per cent of all email traffic on Sunday 22 August.

A company spokesman said that the company's figures are based on its own clients. He said: "Many of our customers come to us because they have a problem, so of course they will be the worst hit of all. We do some major schools' projects and they are the worst hit of any type of organisation."

And, of course, with everyone off to sit around Heathrow in hopes of getting somewhere in August, the number of legitimate emails floating around is likely to be much less - boosting the proportion of spam.

The company found that the average daily quantity of legitimate email for August was just 12.45 per cent. The peak day for legitimate email was Monday 2 August, with 18.34 per cent.

Neil Hammerton, Email Systems managing director, said in a statement: "We have also witnessed that the nature of spam is continuing to evolve, with pornography on the decline and drugs and gambling both significantly increasing."