Businesses that use email marketing have been advised to step up their focus on data security.
According to Econsultancy, a "worrying" number of firms are failing to do all they can to tackle potential risks.
This means many could be leaving themselves vulnerable to a data breach, which could be costly both in financial and reputational terms.
Linus Gregoriadis, research director at Econsultancy, commented: "Companies should address their data security policies now in order to avoid a world of pain further down the line."
The organization noted that a number of simple procedures such as implementing IP restrictions and authenticated logins can help to tackle the threat.
However, figures from Econsultancy showed that only a minority of businesses are using these methods, while many are unsure if these processes are in place at their firm.
The findings come after research by Edelman revealed nearly three-quarters of consumers have become more worried about data security and privacy since 2007.
Posted by Rachel Wheeler