The company submitted a complaint with the National Arbitration Forum on August 18, 2011,asserting legal rights over the disputed domain name.
Yahoo owns many trademark registration for the Yahoo mark.Therefore,they contended that the domain name is confusingly similar with its trademark.Moreover,they contended that the respondent registered and used the disputed domain name in bad faith.
"Complainant argues that since it offers anti-spam services, Respondent’s resolving website that also provides information on eliminating spam competes with Complainant and disrupts Complainant’s business by diverting Complainant’s potential customers away from Complainant’s own website. "
The Panel ordered the disputed domain name be transferred from the respondent to the complainant .
You can read the decision here .



