Answer
GFI Archiver has a soft limit of 2000 mailboxes per installation. For evaluating customers who wish to archive email for more than 2000 mailboxes, multiple deployments of GFI Archiver may be required - these may be departmental or location based, where each location or department would have its own GFI Archiver installation. The performance of GFI Archiver in these environments is dependent on the customer's mail flow and usage requirements.The full guide can be found here:
https://my.gfi.com/ts/Shared%20Documents/Product%20Information/MailArchiver/GFIArchiver_LargeInstalls_en.pdf
It contains guidelines in regard of hardware specs and configuration suggestions.
Notes
- This guide should not be distributed outside GFI
- It should be used when dealing with large install bases individually
- This document is also available to resellers via the GFI Partner Area