Hi there!
If I log in as root and add an FTP user to a domain, I get the possibility to specify a web directory as "Home directory" under "Quota and home directory settings".
However, if I log in as the domain administrator, I am not given such an option.
I have searched for the domain settings and permissions, but found nothing…
Can anyone give me a tip here? Am I missing something or is this a bug? 
While I haven’t figured out your SpamAssassin issue yet, this one I think I can help with 
If you log into Virtualmin as root, and go into System Settings -> Module Config, choose Server Administrator Permissions, I think "Can select home directories for users?" is what you may want there.
-Eric
ohhh ok… well that option also allows to set homes for mail users etc… so i guess i’ll better leave it off 
thanks!