Browser-based mail, calendar, contacts, and document suite from Open-Xchange AG in Cologne, deployed by hosters and public-sector bodies.

OX App Suite is the groupware and productivity platform of Open-Xchange AG, registered at Erftstr. 15–17 in Cologne, Germany (HRB 95366, Amtsgericht Köln), with further offices in Nuremberg, Hamburg, and Olpe. Its shareholders include United Internet, eCAPITAL, and BayBG.

The suite covers webmail, calendar, contacts, task management, file storage, and collaborative document editing. Unlike the self-service suites in this category it is sold primarily to service providers and public-sector bodies, which is why many European mailbox offerings are OX App Suite under a different brand. Open-Xchange also publishes Dovecot Pro and PowerDNS.