I'm trying to use preauth here and for testing-purposes, I'm computing the preauth-URL on my PC and paste it into the browser.
Currently, I only get 400 errors back (authentication failed) - but I don't see any error-messages in the logs as to hint where I may have made a mistake.
I'm trying both the admin-interface (7071) and the normal webmail.
We have a multi-server setup.
BTW: the wiki should be updated with the latest version of the preauth.txt file in p4....