NTT Docomo cracks down on I-mode spammers

NTT Docomo is looking to crack down on spammers who take advantage of the company’s I-mode mobile network to distribute spam e-mails to its subscribers.

The move comes in response to the growing volume of spam being sent over the I-mode network, which has 44 million subscribers, the company said.

In the past, the majority of spam e-mails sent to subscriber handsets over the I-mode network came from personal computers, the company said in a statement. To stem this flow of spam from PCs to mobile handsets, Docomo asked I-mode users to modify their user preferences to accept e-mail only from designated domains or e-mail addresses. The company also began blocking e-mails that were sent to a large number of invalid I-mode e-mail addresses.

As is so often the case in the battle against spam, the spammers responded to Docomo’s moves by changing tactics, sending e-mails from I-mode handsets rather than from PCs, Docomo said. Now, Docomo is ready to strike back with policies intended to punish I-mode subscribers that use their handsets to distribute spam.

A customer complaint about spam sent from an I-mode handset will result in the temporary suspension of all I-mode services to the offending subscriber, the company said. The precise length of time for which services will be suspended was not revealed in a statement distributed by the company.

If the offending subscriber continues to send spam from their I-mode handset, a second customer complaint will result in a cancellation of the offender’s I-mode subscription, the company said.