Already got feedback. In short, upstream doesn't seem a problem with their software not supporting a major webdav server out of the box, and also suggests changing the server, something that is not possible in most corporate environments with IIS. Will Ubuntu make the necessary changes to make Ubuntu useful in a corporate environment? My current solution is to use Windows when I am forced to use the webdav server in my environment. Comment from upstream below. Update of sr #110254 (project davfs2): Severity: 4 - Important => 3 - Normal Status: None => Wont Do Assigned to: None => wbaumann _______________________________________________________ Follow-up Comment #1: davfs2 already has option add_header to add this header if required. It might be a good idea to read the documentation before writing patches: "man mount.davfs", "man davfs2.conf", "man umount.davfs". davfs2 will not by default send vendor-specific non-standard headers. You have to configure them if needed. Hint concerning file extensions: When I tested with IIS many years ago IIS would only deliver files with extensions that were registerd as known extensions with the windows operationg system. So I could upload (with PUT) a file with extension .odt and the file was stored on the server. But when I tried to retrieve the file with GET I got 404 NOT FOUND. You might have to change the server configuration to solve problems with file extensions. On Wed, 1 Jul 2020 at 16:01, Woodrow Shen