I think it said something about it potentially destroying your email. This bug only affects Outlook Express Version 4.01 for the Macintosh. This problem became publicly known in late September of 1998, so it's not exactly new , but it didn't receive a lot of publicity, either. This bug is rare. Not only is it limited to a specific version and a specific operating system, but it only occurs when you use e-mail filters and have very little space left on your hard drive.
Filters are sets of instructions that determine how e-mail programs deliver specific messages.
If you are using Mac Outlook Express 4.01, and you use filters, and your hard drive is low on disk space, then some of your e-mail can become lost forever . If there are too few bytes on the hard drive, Outlook Express will remove the message from the Inbox, but it won't deliver the mail to the folder specified by the filter. As soon as Microsoft announced this bug, they made a patch available online. If you have MacOE4.01, you should immediately upgrade to MacOE4.02 or higher. Microsoft has a MacOE Web site where you can download newer versions.