I noticed the following this week. No idea how long its been happening because I have not tested deleting folders hardly at all. Steps to reproduce:
- Create a folder "NewFolder", click on it in thunderbird so an index dir is created:
ls -ldi Maildir/.NewFolder/ 1504062 drwx------ 5 mcdouga9 egrstaff 4096 Nov 16 19:44 Maildir/.NewFolder/
ls -ldi Maildir/dovecot/boomhauer/private/indexes/.NewFolder/ 4198832 drwx------ 2 mcdouga9 egrstaff 4096 Nov 16 19:44 Maildir/dovecot/boomhauer/private/indexes/.NewFolder/
ls -li Maildir/dovecot/boomhauer/private/indexes/.NewFolder/ total 0 4198833 -rw------- 1 mcdouga9 egrstaff 128 Nov 16 19:44 dovecot.index.log
- Delete "NewFolder" which makes Thunderbird move both the folder under Trash, and seems to "rename" the .NewFolder index dir to .Trash.NewFolder (same inode #): ls -ldi Maildir/.Trash.NewFolder/ 1504062 drwx------ 5 mcdouga9 egrstaff 4096 Nov 16 19:44 Maildir/.Trash.NewFolder/
ls -ldi Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder/ 4198832 drwx------ 2 mcdouga9 egrstaff 4096 Nov 16 19:44 Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder/
ls -li Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder/ total 4 4198833 -rw------- 1 mcdouga9 egrstaff 128 Nov 16 19:44 dovecot.index.log
- Right click on Trash folder in Thunderbird, choose "Empty Trash":
Nov 16 19:47:25 boomhauer dovecot: IMAP(mcdouga9): unlink_directory(/home/mcdouga9/Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder) failed: Directory not empty
ls -ldi Maildir/.Trash.NewFolder/ 1504062 drwx------ 5 mcdouga9 egrstaff 4096 Nov 16 19:44 Maildir/.Trash.NewFolder/
ls -ldi Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder/ 4198832 drwx------ 2 mcdouga9 egrstaff 4096 Nov 16 19:47 Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder/
ls -li Maildir/dovecot/boomhauer/private/indexes/.Trash.NewFolder/ (sometimes has a .nfs.blahblah file, I think I failed to catch it quick enough this time)
The folder dissapears from Thunderbird's view but stays on disk, and will reappear in Thunderbird if you collapse and re-expand the folder tree, or close and open thunderbird. Repeatable after more "Empty Trash" or directly trying to delete the folder in thunderbird from in Trash.
# 1.1.beta8: /usr/local/etc/dovecot.conf ssl_cert_file: /usr/local/etc/apache2/ssl/mail.egr.msu.edu.pem ssl_key_file: /usr/local/etc/apache2/ssl/mail.egr.msu.edu.pem login_dir: /var/run/dovecot/login login_executable: /usr/local/libexec/dovecot/imap-login verbose_proctitle: yes first_valid_uid: 1000 first_valid_gid: 1000 mail_extra_groups: postlocal mail_location: maildir:%h/Maildir:CONTROL=%h/Maildir/dovecot/private/control:INDEX=%h/Maildir/dovecot/%q/private/indexes mmap_disable: yes dotlock_use_excl: yes mail_nfs_storage: yes mail_nfs_index: yes mail_plugins: acl fts fts_squat mail_log_max_lines_per_sec: 0 imap_client_workarounds: delay-newmail netscape-eoh tb-extra-mailbox-sep namespace: type: private separator: / inbox: yes list: yes subscriptions: yes namespace: type: private separator: / prefix: mail/ hidden: yes subscriptions: yes namespace: type: private separator: / prefix: Mail/ hidden: yes subscriptions: yes namespace: type: public separator: / prefix: #shared/decs/ location: maildir:/egr/mail/shared/decs:CONTROL=%h/Maildir/dovecot/public/control/decs:INDEX=%h/Maildir/dovecot/%q/public/indexes/decs list: yes subscriptions: yes auth default: passdb: driver: pam userdb: driver: passwd args: system_user= socket: type: listen client: path: /var/spool/postfix/private/auth mode: 384 user: postfix group: postfix plugin: acl: vfile:/usr/local/etc/dovecot-acls:cache_secs=10 fts: squat