CYBERMAIL Sigma is a cloud email service from Cyber Solutions, a company specializing in corporate email systems. Built for mid-sized to large Japanese businesses, it runs across multiple domestic data centers and tackles common workplace concerns such as eliminating password-protected ZIP attachments (known as PPAP in Japan) and stopping emails sent to the wrong recipient.

Optional safeguards include a brief delay before messages are sent, manager sign-off for external emails, and automatic BCC conversion to reduce accidental exposure of recipient lists. The service can also scan encrypted ZIP attachments for viruses, something most virus checkers skip. A free trial is available.

Organizations can manage email for multiple group companies or brands from a single control panel, with fine-grained admin permissions for each domain.

Webmail is included and works on both desktop and mobile browsers. Dedicated iOS and Android apps are also available.

IMAP and POP3 are supported for connection from standard email clients such as Outlook and iPhone Mail.

Cyber Solutions holds ISO/IEC 27001, 27017, and 27018 certifications, covering information security, cloud security, and personal data protection.