Bain Capital, a leading private equity firm, agreed to acquire MailPublisher, the Japanese e-mail service provider business of Cheetah Digital, a marketing solutions provider. Financial terms were not disclosed. MailPublisher has industry-leading technologies in the growing digital marketing space. It is distributing 6.1bn e-mails on a monthly basis and is introduced to more than 5.3k companies in total. MailPublisher has established a critical infrastructure to its customers, and is maintaining the top share in the e-mail service provider market for the 11 consecutive years. "MailPublisher of Cheetah Digital has an exceptional functionality delivering a large volume of e-mails at high speed, with high security, and without delivery failure. Bain Capital will be providing active support for their further growth, including the expansion of new functions." Yuji Sugimoto, Bain Capital Managing Director.