>My client is thinderbird
Thunderbird is not a valid Webdav Client, as Webdav is HTTP based. Thunderbird is an email client, not a HTTP client.
In order to run a test, you need a Webdav Client, what means, you need a HTTP Client - a browser. Like IE, Firefox, Opera etc.
But: as far as I know, Webdav support is not very good by these browsers (I am not sure, if it runs properly in any of these clients). The best suited browser seems to be "Konqueror", part of the KDE package of Linux.
Nevertheless: Thunderbird won't work anyway. You should read some more documentation about Webdav and implementation of Webdav.