Extending storage space for Briefcase

[tenpagyatso]

Being an arts college we have a unique need based on the volume of digital media being shared between faculty and students. I'd like to use Briefcase for this but use it outside of the quotas assigned within the COS for each of these groups.

Instead of simply adding more storage to the array being used for Zimbra email, is it possible to mount additional storage directly to where Briefcase stores its files? Is Briefcase's file storage organized by and/or within the users' mail storage or can this be 'broken out of' the storage capacity of the system's quota?