All groupware items are stored on the IMAP server as individual emails. The groupware data is coded XML and stored as an attachment in the email.

The XML format used is based on the Kolab Storage Format Version 2.0, the specification of which can be found at https://www.intra2net.com/en/download/manuals/kolabformat-2.0.pdf.

Additionally, the Intra2net Groupware Client stores application specific data as email headers. Their names begin with X-mxstore and X-Sync. The format of these headers may change at any time without notice. These headers should therefore not be interpreted by other software.