If you save edited files in Online Office, they will be stored in
your GMX File Storage.
These are the storage options in Online Office:
Online Office operates with the feature "AutoSave"
to automatically save any changes that have been made during editing the
If you still want to save your file manually, either click File → Save or click the floppy disk symbol.
The file management for Online Office is solely done in
File Storage. If you want to open and edit locally stored
files in Online Office, they need to be uploaded to your
File Storage prior to that. This applies to e-mail file
attachments as well. They can be opened and edited in Online Office after being stored in your GMX