Anti-spam Trend Micro software filters 'P'

Trend Micro's anti-spam software recently took issue with the letter 'P'. A bug, which appeared in an anti-spam rule update, began blocking and quarantining all incoming and outgoing messages containing the letter, depending on how customers had configured the software.

The flaw affected a Trend Micro product designed to filter content, block unsolicited commercial email, and report and monitor the type of information that enters or leaves a company's network.

The problem affected the company's eManager product, an email security tool. A company representative said the number of customers who reported being affected was in the low double digits.

The problem occurred in rule number 915, which updates anti-spam parameters. The security firm quickly released a fix with rule number 916 and posted it to its site last Tuesday. Rule number 915 was available for only an hour and a half before Trend Micro issued rule number 916.

Spam is considered one of the biggest drawbacks of internet communications, wreaking havoc on computer users and on ISPs whose systems are inundated by messages. In effect, spam depreciates the value of email by flooding it with an enormous volume of pornographic and get-rich-quick solicitations.

Anti-spam rules are updated frequently to keep pace with spammers who routinely fool filters by tweaking the contents, addresses and subject lines of their messages.

Sandeep Junnarkar writes for CNET News.com.