OLFolderSync can synchronize any Microsoft Outlook folder with anyone else's (except for Drafts, Outbox, Sent Items and Deleted Items). Synchronization of these folders runs as a background process facilitated by OLFolderSync synchronize messages. This allows you to easily synchronize Outlook folders via the Internet whithout the need for both parties to be online at the same time. When a new item is created or modified in an outlook folder, OLFolderSync automatically creates and sends a synchronization-email (i.e. a special e-Mail) detailing the item to specified others users. This synchronization-email is then automatically processed by remote user's previously installed OLFolderSync add-in which knows the target for the embedded item.
Synchronization can be limited to specific Outlook categories and, whether to include private items. All items which have holiday as category will not be synchronized.
Read The publisher description in: French