Supported by: 
As of DME 3.6, the E-mail folder sync. setting is always enabled, and it has been removed from the Settings page.
With e-mail folder synchronization you can synchronize e-mails from any folder in your collaboration system mailbox, instead of only from the Inbox. As for the Inbox, you can limit the number of synchronized e-mails in folders by specifying a maximum age of the e-mails to be synchronized. This is specified as a default number of days for all e-mail folders, but you can allow the number to be changed on a per-folder basis on the clients. Furthermore, you can specify if you want to receive notification of new e-mails in sub-folders - for instance, if a mailbox rule on the collaboration system automatically moves incoming e-mails to sub-folders, you will not receive a notification unless you choose to. See also Allow individual settings below.
If this field is set to Enabled, scheduled synchronization of folders on your collaboration system is enabled. When enabled, the folder tree structure will be made part of the synchronization of e-mails. Note that the synchronization of the folder tree structure is one-way; the folder structure on the device will always be updated to reflect the collaboration system, as it is not possible to create or delete folders on the device.
If you use Lotus Domino as your collaboration system, please note the following:
- In Domino, it is possible to have the same document (e-mail) located in multiple folders - it is essentially the same document, and therefore it has the same ID in the collaboration system. In DME, an e-mail is only shown in one location in the mailbox folder tree, even if it has been copied to multiple folders in Domino.
- S/MIME messages sent from the device will not be deleted from the Sent mailbox folder on the client even if it is removed in Lotus Notes. It must be removed manually from the client if desired.
- In Lotus Notes, you cannot manually move an e-mail to the Sent mailbox folder. This is possible in the DME client (even if not recommended).
Furthermore, if you send an e-mail from the device, the e-mail is moved to the Sent mailbox folder on the device, even if the collaboration system is for some reason unable to send it after synchronization.
- Days back in folder (default value)
In this field you can specify how many days back the DME client should synchronize e-mails in sub-folders, when this is enabled. By default, the permitted range is from 0 to 99 days, but you can change this. Note that with higher numbers, the load on the DME server will increase. Note also that this number may be overwritten on a per-folder basis on the device, if the field Allow individual settings below is selected. Recommended value: 1.
- Sync. e-mail in folder (default value)
If this setting is On, synchronization of the e-mails residing in folders is enabled. When this setting is On, the actual e-mails in the folders are included in the synchronization. If this setting is Off, e-mails in folders are never synchronized, only the folder structure. Note that this setting may be overwritten on a per-folder basis on the device, if the field Allow individual settings below is also On.
- Scan folder for changes (default value)
If this setting is On, folders are scanned for the arrival of new e-mails on the server. If folder scan is not enabled, users will not receive notification of new e-mails in sub-folders on the collaboration system. It is recommended to let the individual clients determine which folders it is necessary to receive notifications for. See Allow individual settings below.
- Maximum folders on device
In this field you can specify the maximum number of folders to be synchronized to the clients. Symbian devices cannot handle large numbers of folders (more than about 300-500), and they will crash if this number is exceeded. The actual number of possible folders differs from device to device, but is usually somewhat higher than 300.
There is no way to specify that an "unlimited number" of folders is allowed. To work around this, you can enter a large number (for instance 10,000) in this field.
Please note that your collaboration system determines which folders are synchronized to the client if you have more folders than specified in this field. IBM Domino will synchronize as many entire sub-folder "trees" (a "tree" being a root folder and all folders contained in it, at all levels) as possible, in alphabetical order by root folder, until the folder limit is reached. Microsoft Exchange will synchronize folders by age - that is, the oldest folders up until the folder limit are synchronized to the devices.
If you set this field to 0 (zero), the folder structure will not be available for searching for e-mails from the client either.
- Allow individual settings
If this setting is On, the DME users can modify the e-mail folder synchronization settings on a per-folder basis. From the server, you can only allow or disallow the synchronization of e-mail in all sub-folders. To set up e-mail folder support in the most efficient way, it is recommended that you enable e-mail folder synchronization, disable the synchronization of e-mails in folders, and enable this field to allow the users to pick which folders they need to keep synchronized.
Please note that if you change this setting from On to Off, all folders with individual settings on a device will be overwritten with the default settings on the client devices. Note also that if a device user chooses to import folders, the same thing happens - all individual folder settings will be overwritten, and the user must redefine individual settings on a per-folder basis.
Furthermore, the client contains a function called Apply to all folders now. When that function is selected, the settings for Days back and Sync. e-mail in folder in the Settings > Folders window/tab are propagated to all e-mail folders on the client.