I have setup a Toaster version 5.03 on Freebsd 6.1 and I have it up and running well. I am using it to host two domains now and more to come. I have noticed one interesting thing about the secure login page that is provided to access qmailadmin and the various webmail clients. It will take whatever login you give it and log you in. Once in if you click around you can not access anything unless the account you logged in with is legit but it does not error out or anything when inputting a bogus user or password.
It doesn't "log you in", it simply saves the values. It needs to test them, but that code hasn't been written yet.