We have upgraded today from Dovecot 2.2.31 to Dovecot 2.2.33.2 and modified our config to include ITERINDEX in mail_location and we are detecting some errors like this:

/Dec 13 08:17:31 buzon_rhel7 dovecot: imap(rboloix): Error: stat(/buzones/location/18/48/rboloix/mailboxes/SIT - Pra&AwE-cticas 2014/dbox-Mails) failed: No such file or directory// //Dec 13 08:40:24 buzon_rhel7 dovecot: imap(espi): Error: stat(/buzones/location/11/21/espi/mailboxes/CURSOS/ACCION SOCIAL/dbox-Mails) failed: No such file or directory// //Dec 13 08:40:25 buzon_rhel7 dovecot: imap(espi: Error: stat(/buzones/location/11/21/espi/mailboxes/CURSOS/ACCION SOCIAL/dbox-Mails) failed: No such file or directory// //Dec 13 08:41:59 buzon_rhel7 dovecot: imap(espi): Error: stat(/buzones/location/11/21/espi/mailboxes/CURSOS/ACCION SOCIAL/dbox-Mails) failed: No such file or directory/

    I have grepped logs of past 4 weeks and have not found this errors with Dovecot 2.2.31. Any idea of what is going on?

    Full doveconf -n output below:

/# 2.2.33.2 (d6601f4ec): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.21 (92477967) # OS: Linux 3.10.0-693.11.1.el7.x86_64 x86_64 Red Hat Enterprise Linux Server release 7.4 (Maipo) xfs auth_cache_negative_ttl = 10 secs auth_cache_size = 10 M auth_cache_ttl = 2 mins auth_master_user_separator = * auth_mechanisms = plain login auth_worker_max_count = 5500 base_dir = /var/run/dovecot/ default_client_limit = 5000 default_process_limit = 6500 disable_plaintext_auth = no imap_capability = +XLIST imap_client_workarounds = tb-extra-mailbox-sep delay-newmail tb-lsub-flags lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes mail_fsync = never mail_gid = entrega mail_home = /buzones/location/%2.26Hn/%2.200Hn/%n/home_usuario/ mail_location = mdbox:/buzones////location//%2.26Hn/%2.200Hn/%n:ITERINDEX:INDEX=/indices_dovecot/indices/%2.26Hn/%2.200Hn/%n:ALT=/buzones/alternativo////location//%2.26Hn/%2.200Hn/%n mail_max_userip_connections = 15000 mail_plugins = " zlib acl quota virtual mail_log notify" mail_uid = entrega mailbox_list_index = yes managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date mdbox_purge_preserve_alt = yes mdbox_rotate_interval = 1 days mdbox_rotate_size = 60 M namespace { inbox = yes location = mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox SPAM { auto = subscribe special_use = \Junk } mailbox Sent { auto = subscribe special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = type = private } namespace { list = yes location = mdbox:/buzones////location//%%2.26Hn/%%2.200Hn/%%n:ALT=/buzones/alternativo////location//%%2.26Hn/%%2.200Hn/%%n:INDEX=/indices_dovecot/indices/%%2.26Hn/%%2.200Hn/%%n:INDEXPVT=~/mdbox/carpeta_compartida/%%u prefix = carpeta_compartida/%%u/ separator = / subscriptions = no type = shared } namespace { list = yes location = virtual:/etc/dovecot/virtual:INDEX=~/mdbox/virtual:CONTROL=~/mdbox/virtual prefix = Carpetas_virtuales/ separator = / } passdb { args = /etc/dovecot/deny deny = yes driver = passwd-file } passdb { args = /etc/dovecot/dovecot-ldap.conf driver = ldap } passdb { args = /etc/dovecot/dovecot-ldap.conf driver = ldap } plugin { acl = vfile acl_shared_dict = file:/buzones////location//acls_compartidas.db lda_mailbox_autosubscribe = yes mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename mail_log_fields = uid box msgid size subject from quota = dict:Cuota de usuario::file:/buzones/cuotas/%n quota_rule2 = Trash:storage=+10%% quota_warning = storage=90%% aviso_cuota 90 %u sieve = /buzones////location//%2.26Hn/%2.200Hn/%n/home_usuario/dovecot.sieve sieve_dir = /buzones////location//%2.26Hn/%2.200Hn/%n/home_usuario/sieve/ zlib_save = gz zlib_save_level = 9 } pop3_no_flag_updates = yes protocols = pop3 imap sieve service anvil { client_limit = 25000 } service auth { client_limit = 32000 unix_listener auth-master { user = entrega } unix_listener auth-userdb { user = entrega } user = root } service aviso_cuota { executable = script /usr/local/bin/quota-warning.sh unix_listener aviso_cuota { mode = 0666 } user = entrega } service config { process_min_avail = 4 } service imap-login { executable = /usr/libexec/dovecot/imap-login group = dovenull process_min_avail = 2 service_count = 0 vsz_limit = 1 G } service imap { executable = /usr/libexec/dovecot/imap process_limit = 8000 process_min_avail = 12 vsz_limit = 1 G } service managesieve-login { executable = /usr/libexec/dovecot/managesieve-login inet_listener sieve { port = 2000 } process_limit = 2000 vsz_limit = 1 G } service managesieve { executable = /usr/libexec/dovecot/managesieve process_limit = 5000 } service pop3-login { executable = /usr/libexec/dovecot/pop3-login process_limit = 5000 process_min_avail = 2 service_count = 0 vsz_limit = 1 G } service pop3 { executable = /usr/libexec/dovecot/pop3 process_limit = 5000 } ssl_ca =