Problem with Filemanager compressor

[interfasys]

I tried to compress the root folder of one account and here is what I got.

Error while compressing file:
/usr/bin/tar: imap/domain.com/user/mail: Cannot savedir: Permission denied /usr/bin/tar: Error exit delayed from previous errors

I've checked permissions in that user folder and mail can only be accessed by root :

2 drwx------ 2 root user 512 Sep 23 05:59 mail