iPhone with multiple email folders syncs only the Inbox automatically
Posted by - NA - on 30 June 2009 04:37 PM

iPhone/iPod Touch:

iPhone/iPod touch devices with multiple email folders tagged for synchronization, will synchronize only the Inbox folder automatically.  

If folder mirroring is enabled on the server, the folders you select for synchronization appear in the Mailboxes list.  The Inbox is the only folder that synchronizes automatically.  On devices running OS 3.0 or later, however, you may select other folders (excluding Trash) to also synchronize automatically.

Select Settings > Mail, Contacts, Calendars > (account) > Mail Folders to Push, then check the folders you wish to automatically synchronize.

On devices running OS versions older than 3.0, folders other than Inbox will initiate synchronization only when they are opened or when using the reload icon (manually initiated sync).  

On devices running 2.0 through 2.2.1, other folders must be opened in order to initiate synchronization.
If one of these folders is already open, the user must tap the reload icon to continue retrieving  

Further testing with iPhone version 2.2.1 reveals that this holds true when the device is in Push mode and that merely entering the Mail application initiates a fetch for messages in folders other than the Inbox.
If the synchronization mode is changed to Fetch, however, the device checks for messages in both the Inbox and other folders at each scheduled synchronization session.  This may serve as a workaround for users not requiring Push mode delivery.

Read more about iPhone Push and Fetch modes at: