However, cunning spammers are setting up fake domains to send their spam messages. This is achieved by forging other carriers’ domain names, which disguises the mail as originating from a cellular or PHS phone. DoCoMo hopes to address the problem by upgrading its i-mode center to block forged-domain spam mail.

Once the countermeasures are in action, customers will no longer need to nominate company domains to receive mail from cellular or PHS phones. This will increase the available number of designated domains, which will be more convenient for i-mode users.