NANJING, Nov. 8 (Xinhua) -- Chinese anti-virus software company Ruixing on Saturday promised help for users to restore lost e-mail, after a bug appeared on the company's anti-virus software that supports Microsoft's Outlook Express mailboxes.

    "Ruixing's engineers worked overnight to produce a mail-restoring tool that users can download and restore the mail," said spokesman Ma Gang.

    The Beijing-based firm issued a public apology on Friday, admitting the bug in its software, Kaka, caused Outlook's automatic elimination of users' mail lists and cookies.

    Industry experts said the bug might have caused widespread mail losses affecting millions of Outlook users, while the company estimated that the actual number of computers affected was probably in the thousands.