WebARENA Mail Hosting is a cloud email service from NTTPC Communications, an NTT Group company. It targets mid-sized to large organizations and has been adopted by local governments, schools, and medical institutions across Japan.

All hardware is doubled so that a single server failure does not interrupt mail processing, and each customer gets their own isolated virtual server. An AI-based security layer helps block targeted attacks before they arrive, while SPF, DKIM, and DMARC settings can be managed from the control panel. A free trial is available.

Custom domain email is supported, with the ability to manage multiple domains and DNS records from the admin panel.

A webmail interface is included and works on both desktop and mobile browsers.

Both IMAP and POP3 are supported for use with standard email clients.

NTTPC Communications holds ISO 27001 certification for information security management.