Hello,
We have 3 nodes running, with a two way replication between 2 of them and a 1 way replication to a DR node running off one. We use mdbox, and directors to split traffic across nodes. There is no shared file system. Users are experiencing messages reappearing in their INBOX as unread with duplicate GUID and message headers. This occurs generally several days after a message was first received (and often actioned; read, moved, trashed, expunged, also often bulk moved/deleted). We have attempted to remove replication from the equation by cutting down to one single node with all replication disabled which did not have any impact. We have also started regular cache and mailbox purging. There are no logged events when mail items reappear, and we only observe it based on user report, mailbox inspection (doveadm looking for duplicate GUIDs/unique message headers) or seeing IMAP commands being done against the same message twice (e.g. monday they copy to trash, delete and expunge from inbox, delete and expunge from trash, then the next monday they will have to do the same for the reappearing message). OS: Centos 7 Dovecot: dovecot -version Scheduled jobs: */15 0 * * 0 doveadm sync -u "*" tcps:<dr node>:12345 > /var/log/dovecot/dr_sync.log 2>&1 1 3 * * * doveadm mailbox cache purge -A INBOX 21 3 * * * doveadm mailbox cache purge -A Trash 0 1 * * 0 /usr/bin/doveadm purge -A >/dev/null 2>&1 Conf: dovecot -n # 2.3.16 (7e2e900c1a): /etc/dovecot/dovecot.conf # OS: Linux 3.10.0-1160.53.1.el7.x86_64 x86_64 CentOS Linux release 7.9.2009 (Core) # Hostname: <primary node> auth_master_user_separator = * default_vsz_limit = 1 G disable_plaintext_auth = no dotlock_use_excl = no doveadm_password = # hidden, use -P to show it listen = * mail_fsync = always mail_location = mdbox:~/mail mail_nfs_index = yes mail_nfs_storage = yes mail_plugins = " notify replication" mmap_disable = yes namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { autoexpunge = 30 days special_use = \Trash } prefix = separator = . } passdb { args = /etc/dovecot/conf.d/passwd.masterusers driver = passwd-file master = yes } passdb { args = /etc/dovecot/conf.d/passwd.masterusers driver = passwd-file } plugin { mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename save flag_change mail_log_fields = uid box msgid size flags mail_log_group_events = mail_replica = tcps:<second node>:12345 } protocols = imap service aggregator { fifo_listener replication-notify-fifo { mode = 0666 user = vmail } unix_listener replication-notify { mode = 0666 user = vmail } } service doveadm { inet_listener { port = 12345 ssl = yes } } service imap-login { inet_listener imap { port = 144 } inet_listener imaps { port = 994 ssl = yes } } service replicator { process_min_avail = 1 unix_listener replicator-doveadm { mode = 0666 } } ssl = required ssl_cert = </etc/pki/dovecot/certs/dovecot-internal.pem ssl_cipher_list = TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA ssl_client_ca_file = /etc/ssl/certs/ca-bundle.crt ssl_dh = # hidden, use -P to show it ssl_key = # hidden, use -P to show it ssl_prefer_server_ciphers = yes userdb { args = /etc/dovecot/conf.d/dovecot-dict-auth.conf.ext driver = dict } userdb { args = /etc/dovecot/conf.d/dovecot-ldap.conf.ext driver = ldap } protocol imap { mail_max_userip_connections = 9999 mail_plugins = " notify replication mail_log notify" } Any thoughts would be greatly appreciated. Thanks in advance, Andrew