Spammers are less than a year away from mass-mailing messages with personalised subject lines, greatly increasing the chances of users opening the message, a security expert warned today.

Technical staff, for example, are currently receiving messages with subject lines such as 'DNS change request'.

Matt Sergeant, senior anti-spam technologist at MessageLabs, believes this is a trial run for more widespread spam using the same social engineering principles. 

"The end game is for spammers to pull together information from the site where they harvested your address and generate highly specific subject lines using text automatically extracted from the source," he told vnunet.com. 

Such an email stands a greater chance of slipping through a single-technology filter such as the Bayesian spam filter in Mozilla's Thunderbird email client favoured by many techies.

The spammers will still be sending out millions of emails, but each one will be personalised for the target. Such a scenario is "six to 12 months away", Sergeant believes.

Earlier this month, MessageLabs warned about targeted phishing attacks using personal information harvested from social networking sites like MySpace. 

The best way to protect against such attacks is to use email filters that deploy more than one technique, according to Sergeant.