Pornographic spam email dropped by a huge 92.5 per cent during February, while unsolicited emails offering dating services surged by 171 per cent, newly published research has claimed.

Email management firm Email Systems said that the surge in dating spam last month was accompanied by a steep increase in unsolicited email offering financial services, which jumped by 107 per cent.

The research indicated that spam as a whole continued to increase last month, with an average of 92.08 per cent of all incoming email being identified as unsolicited, compared with an average of just under 90 per cent during January.

The figures represent the first monthly average above 90 per cent. On 6 February, the worst point during the month, spam reached a staggering 97.6 per cent of all email traffic. Combined with 0.61 per cent of virus traffic on that day, fewer than one in 55 emails were legitimate.

On 24 February, legitimate email comprised just 12.42 per cent of all email, with spam at 85.83 per cent and virus traffic at 1.74 per cent.

Medical and pharmaceutical related spam was identified as the most prevalent type of unsolicited mail, representing almost one in two of all spam mails.

Other prevalent spam categories detected during February included educational/degree offers, cheap software, travel and religious emails.

Neil Hammerton, chief executive at Email Systems, said: "The drop in pornographic spam is incredible considering that this type of email was the most prevalent spam just over a year ago.

"The change indicates how spam as a whole has shifted towards overtly promoting scams, financial incentives, cheap products and other consumer-focused opportunities in an attempt to encourage mainstream recipients to part with their cash.

"In contrast to the ever increasing spam numbers, the virus figures seem extremely low by comparison.

"However, although the proportion has decreased, the amount of virus traffic has actually increased since late 2004, which again underlines the massive quantities of spam that are now being distributed each day."