NTT Docomo isn’t having much luck with its SP-mode smartphone email service lately. After being hit by an email address-shuffling bug affecting tens of thousands less than two weeks ago, Japan’s largest wireless provider was hit with a new bug late Sunday night that not only made it tough to send emails, but both stopped the emails of about 200,000 subscribers from arriving, and failed to deliver "nondelivery" emails to notify the senders.

The New Year’s holiday is the biggest of the year in Japan, but Docomo claims that a server malfunction was the cause of the problem, and not the millions of New Year's greetings. The company has announced that it's working to prevent a recurrence, although it hasn’t spelled out any specifics. In the meantime, Docomo will be notifying customers of the problem in their upcoming bills, as well as providing a toll-free number for individual inquiries.