Problem retrieving Spam folder

[basbebe]

I have problems retrieving the contents of my Spam folder on an iOS device. It is called "Junk" and I set the IMAP config define('IMAP_FOLDER_SPAM', 'JUNK');. However on an iPhone I don't see any messages in that folder and get an error after a few second. I already did a resync.

Dovecot doesn't throw any errors and Z-Push doesn't tell me anything obvious either. Anything I might check? Thanks!