Sean,

 

Unfortunately, the user data, domains, and mail are all tied together. In the domainList.xml file, it shows the domain name and the location of its directory.  This directory includes all of the user data and their associated mail files.  You cannot move only the user data and domains.  If you wanted to move the entirety of the domain, stop the mailservice, copy the domain or domains you want to move to their new location, modify the domainList.xml for the moved domain changing the directory attribute, then restart the service.

Hello Sean, you can use a standard robocopy script to mirror the domains structure, user directorys, XML configuration files, etc - but exclude GRP/CFG files to leave behind user mail. The GRP files contain mail, and the CFG files index the GRP files. Copy everything aside from these, and you'll have an exact copy of the domain minus mail. The robocopy switch you'd need is: 

 

/xf *.GRP *.CFG