Speaking at the second oral evidence session of the All-Party Parliamentary Internet Group's spam inquiry, Jessica Hendrie-Liano, chairwoman of the ISP Association Council, said the idea that ISPs are happy to process spam is a misconception.
"Spam is a cost to ISPs in terms of time and resources," she said.
Hendrie-Liano outlined the costs ISPs incur by providing spam reporting services and abuse teams, monitoring e-mail systems, deploying and updating software, and the negative effect that spam has on ISPs' hardware.
"Spam causes the computer hardware used to process e-mail to become overloaded," she said. "Not only do these mail servers slow down or stop, but the useful life of these expensive items of hardware is reduced. ISPs face costs for increased maintenance and new equipment as a result of spam."
The ISP Association believes that combating spam requires a co-ordinated global approach that involves users, technology firms and governments.
Hendrie-Liano said, "Spam is a global problem that needs to be tackled by a combination of legislation, technical innovation and education." She added users should take preventative action by using spam filtering software.