There must be huge stockpiles of unused floppy disks somewhere that nobody can sell. That could help with costs.
Backup and restore wouldn't be much slower than BackupExec, I feel.
Seriously though, better, more efficient mailbox storage is the way forward. Of our ~1,500 staff, quotas are always hit and it is down to emails being sent out willy-nilly where the recipient isn't usually relevant but is on a big distribution list. A more efficient database would cover this. 1 mail sent out to thousands of people in the same domain, shouldn't mean thousands of copies of that mail. It should be one copy of the original email with an index referring to the recipients and storing message state, ie read, unread, deleted and so on. Once an email is forwarded, yes it becomes a new email and we go around again.
I thought MS Exchange worked this way, but I have some doubts, at least as to the precise implementation.
Just a suggestion.