reddit

“PostPath is best known as a drop-in replacement for Microsoft Exchange. Unlike other would-be Exchange competitors Scalix and Lotus Domino/Notes, which use a Outlook-compatible Mail Application Programming Interface (MAPI) on the client PC, PostPath actually reverse-engineered Microsoft's MAPI and Active Directory (AD) protocols. This means that, from the network and Windows PC's viewpoint, PostPath actually appears to be an Exchange server.” source...