A public folder job is configured between a source and target server pair to synchronize public folders. The source and target servers for a public folder synchronization job must have local replicas for all folders to be synchronized.
It is highly recommended that you set up and configure all the public folder synchronization jobs before actually starting the synchronization process. If any job requires reconfiguration after it has been started, replication may not run for period of time and some data might be lost because of incorrect reconfiguration.
Whether to Choose One-Way or Two-Way Synchronization
The main decision when setting up a job is whether to choose one-way or two-way synchronization:
CAUTION: If after one-way public folder synchronization is started, you decide to switch it to two-way, the whole public folder content that was transferred to the target will be transferred back to the source. This may cause performance degradation in the agents. Therefore, it is recommended that you do not change the public folder synchronization direction after synchronization starts.
How Many Public Folder Synchronization Jobs are Needed
If you want to migrate your public folders “as is,” you can simply set up one public folder job with All Public Folders as the root of synchronization. However, it may not be possible to have replicas of all folders on a single source Exchange server. In this case, you will have to create several synchronization jobs with different servers as their sources.
Having multiple jobs running in parallel improves the synchronization speed but complicates troubleshooting. It is recommended that you minimize the number of jobs by replicating all source public folders to selected servers. For example, you can use one source Exchange server in each physical location to have replicas of all public folders used in this location. These servers will serve as bridgeheads for public folder synchronization with target Exchange servers.
Public folder agents are installed on each source and target server involved in a public folder synchronization job. A public folder agent can synchronize only folders for which it has a local replica. For this reason, public folder jobs should span a set of servers that have at least one local replica of each source public folder in the source organizations.
When planning public folder synchronization, you should consider that public folders created by the agents on the target Exchange servers will be owned by the account that the Public Folder Target Agent uses. It is recommended that this account be mailbox enabled.
Also, a mailbox must exist on each server participating in public folder synchronization. The public folder agents use a local mailbox to access the public folder data. You should create dedicated mailboxes on the servers that host public folders. These mailboxes should not be included in the mailbox synchronization.
Public folder collections are used to prioritize public folder synchronization. Normally, each job has one collection configured and the public folders in these collections will be synchronized until the end of the migration.
Multiple collections may be associated with each job. Each collection has a priority number starting from 1, which is the highest priority. The collections are processed by the agent in sessions according to their priority number. The agents start processing with the collection that has the highest priority. The collection priority can be changed.
A collection is not processed until all public folders in higher priority collections are in sync. Therefore, multiple collections should be used with care. If data will be continuously synchronized and a high-priority collection has its source folders change frequently, collections with lower priority may not be processed.
Only the default MAPI top level hierarchy in each Exchange organization can participate in public folder synchronization.
You may want to restructure your target Exchange public folder hierarchy so that it is different from the existing source Exchange hierarchy, particularly if you are consolidating Exchange organizations. Migration Manager for Exchange fully supports migration and restructuring even if your source Exchange public folder hierarchies have different structures and in the new environment they will be standardized.
You can specify that a source public folder (and, optionally, subfolders) synchronize with any existing public folder in the target Exchange organization, or you can specify a new folder in the target Exchange public folder hierarchy with which to synchronize data. Migration Manager for Exchange will create new public folders in the target Exchange organization as required.
You can also exclude any folder from a synchronization job (and include it in a job elsewhere if desired).
There may be cases where multiple source public folders (from the same or different Exchange organizations) will be merged into one target public folder. There are limitations in doing this and the result is that the source public folders will have different data.
When an item is added, moved, or deleted in a source public folder, the corresponding change will take place in the target public folder. However, none of the other source public folders will be notified of this change because when the change is made to the item in the target public folder, it is marked in such a way that it is considered to be up to date. Similarly, if an item is changed in the target public folder, this change will be propagated to only one of the source public folders. For this reason, when multiple folders are merged to one target folder, the synchronization direction should be from source to target only.
Even if only one job is configured to participate in two-way synchronization, that source public folder will not contain an exact copy of the target public folder. The agent running on the target is not designed to synchronize back to multiple folders although it can receive updates from multiple source public folders.
Synchronization with Multiple Organizations
Target public folders may be synchronized with folders from multiple source Exchange organizations with the limitations stated above. If there are no source public folders to be merged into the same target folder, then two-way synchronization can be set up between all organizations without issues. The setup of the synchronization jobs must be done carefully so that each public folder in the target unambiguously corresponds to one source public folder.