Our products are normally based on the Exchange server, to make it possible to share data. You can use a mailbox instead of a public folder, but in order to collaborate many people on the same mailbox that mailbox should anyway be hosted on an Exchange server.
There are a couple of non-Exchange public folder servers out there, but we have not tested our applications on those, so we can not make any guarantees. But please try! Since you are allowed to evaluate our products before purchase we encourage you to do so, and we appreciate if you inform us of your experiences.