There is a mindset among many that retaining old e-mails will put a company at risk. Many reason that e-mails handed over to an adversary during e-discovery, for example, will contain a "smoking gun" that could result in embarrassment or the loss of a legal judgment.

In some cases, this mindset has been proven correct. We’ve seen examples in high profile cases over the years of CEOs and others who have said things in e-mail that they wish had not been available for presentation at trial or during pre-trial motions.

However, in most cases it’s better to keep old e-mails, instant messages and other content, even if they do contain information that might reflect poorly on your company. Since it’s virtually impossible to delete all copies of e-mail that are sent outside of your company, you might as well retain them – chances are, someone will have copies of them anyway and you don’t want to walk into court as the only party that is not privy to this information.

In a major study on the archiving market that we have just published, we found that organizations in North America are following this course of action. For example, while 32% of organizations believe that preserving all e-mail content for long periods is the least risky option, 10% believe that deleting all content poses the least risk. 

However, the proportion of organizations that believes that deleting all e-mail is the least risky course of action is dwindling over time. In an archiving study we conducted in 2007, 15% of organizations felt that deleting all e-mail was the least risky option; a study conducted in 2006 found this figure was 23%.

This clearly indicates that organizations' views on data retention are maturing over time and that a “delete everything” mindset seems to be on its way out. This will be particularly important as more organizations migrate to a unified communications model and need to retain even more data.

Michael Osterman is principal analyst of Osterman Research.