Email spam levels are likely to fall in the future but techniques will become more sophisticated and move to newer protocols such as voice over IP, according to an ex-spammer speaking at email security specialist IronPort's customer conference today.

Spammer X, who claims to have made around $350,000 a year from spamming, predicted an increase in image-based spam and the advent of video image spam.

"This is a cat and mouse game so the filters will change and the next generation will have to contend with video content – how do you filter an mpeg? " he argued. "Spam will never go away. You won't get email spam in 20 years time but they'll find different mechanisms to exploit."

Spammer X highlighted internet telephony and video messaging services as the next big areas for spammers to exploit, as they gain in popularity. "By 2015 we'll have video spam and by 2020 it will be a huge problem," he added. "If you think images are a problem then imagine a 60 second advert for Viagra at 25 frames per second – there's no current technology to stop this."

Although he praised current filtering technology as "very smart", the ex-spammer argued that technology solutions are not the answer to the spam epidemic, and that more effort needs to be directed at making it economically unviable to send unwanted mail.

"By keeping PCs secure it reduces the number of bot nets, making them more expensive to hire and reducing the amount of money to be made," he explained. " We also need to catch the enablers of spam – the bot herders, the web site hosters and spammer-friendly internet forums, which will make it harder to get into [the industry]."

Spammer X also warned that in some firms, IT insiders are harvesting staff email addresses and selling them on to spammers.