problem importing external IMAP account

[eleith]

i have a user importing an external IMAP into their zimbra account, and they are running into problems.

i've turned logging on, and my best guess is that it is failing on importing one of the folders.

if fails on importing INBOX/INBOX. (yes, that is a folder named inbox inside the root folder named inbox)

this fails, and then no emails can ever be loaded, and the external imap account has to be deleted.

when i load the external imap account into thunderbird, it complains of some folder, but eventually loads everything accept that folder (which is empty).

thus, we can not delete this folder from another account to further test if this is indeed the problem.

i would think that zimbra should just complain it can not download a folder, but still allow the external imap account to work (minus the bad folder). this seems to be what thunderbird does.

any thoughts on how to progress?