It's easy on the Toshiba to set up different 'Auto Attendants' - you'd simply point a DID at a pilot number, the pilot number would go to the VM - to a specified Mailbox.

So you could have 100 (or any number!) of DID's, all pointing to different mailboxes... and each mailbox would have the greeting for *that* entity, as well as appearing to handle calls as if they were the only ones on that VM.

It can be a tad tricky, however, depending on the VM used, to restrict a caller from being able to access any of the extensions in the system. So a caller could dial extension 200 - even if the person sitting at Ext 200 doesn't belong to *that* company (that the DID was directed at.)

I have one firm that has a dozen different companies within it, and they all have their own main greeting (I used a spreadsheet to keep the spaghetti together!)