I have two dovecot instances that replicate to each other. Mail arrives into "post" and it is generally accessed via IMAP on "france". Changes (moves/expunge etc) on "france" seem to replicate back to "post" more or less immediately. But this seems to happen only for this user. (Some) other users' (e.g. me) mail generally replicates more or less immediately in both directions.

Nov 5 17:40:55 post dovecot: lmtp(willem@xxx): xF9mK6eUO1YsFQAAdYyp2A: sieve: msgid=20151105173923.14970.95605@ssa-app-xxx: stored mail into mailbox 'SSA' Nov 5 17:41:00 post dovecot: lmtp(willem@xxx): yV9mK6eUO1YsFQAAdYyp2A: sieve: msgid=20151105173924.14970.91073@ssa-app-xxx: stored mail into mailbox 'SSA'

Nov 5 20:39:09 france dovecot: dsync-server(willem): save: box=SSA, uid=3130, msgid=20151105173923.14970.95605@ssa-app-xxx, size=9724 Nov 5 20:39:09 france dovecot: dsync-server(willem): save: box=SSA, uid=3131, msgid=20151105173924.14970.91073@ssa-app-xxx, size=9197

Any suggestions as to where to start looking? As you can see I am using 2.2.18 with mdbox and a simple all vmail based system with not many users. I am not seeing any error messages in my mail logs that suggest there any delays happening. Although I have seen a few things like this happening from time to time a busier account:

Nov 5 12:12:07 france dovecot: dsync-server(djk): Error: Couldn't lock /home/imap/djk/.dovecot-sync.lock: Timed out after 30 seconds Nov 5 12:12:13 france dovecot: dsync-server(djk@tobit.co.uk): Error: Couldn't lock /home/imap/djk/.dovecot-sync.lock: Timed out after 30 seconds Nov 5 12:16:49 france dovecot: dsync-server(djk): Error: Couldn't lock /home/imap/djk/.dovecot-sync.lock: Timed out after 30 seconds

root@france:/var/log# dovecot -n # 2.2.18: /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.8 (0c4ae064f307+) # OS: Linux 3.13.0-66-generic x86_64 Ubuntu 14.04.3 LTS auth_verbose = yes doveadm_password = <some secret string or other> first_valid_uid = 2000 imapc_features = rfc822.size fetch-headers imapc_host = <imap hostname> imapc_port = 993 imapc_ssl = imaps imapc_ssl_verify = no imapc_user = %n lda_mailbox_autocreate = yes login_greeting = IMAP ready. mail_attachment_dir = %h/attachments mail_attachment_min_size = 64 k mail_location = mdbox:%h:INBOX=%h/mail mail_plugins = " fts fts_lucene mail_log notify notify replication" mail_prefetch_count = 20 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 index ihave duplicate mdbox_rotate_size = 10 M 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 { special_use = \Trash } prefix = } passdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } plugin { fts = lucene fts_lucene = whitespace_chars=@. mail_log_events = delete undelete expunge copy save mailbox_delete mailbox_rename mailbox_create mail_log_fields = uid box msgid size mail_replica = tcps:post:<same port as doveadm port> sieve = file:~/sieve;active=~/.dovecot.sieve } postmaster_address = postmaster@tobit.co.uk protocols = " imap lmtp sieve sieve" service aggregator { fifo_listener replication-notify-fifo { mode = 0666 user = vmail } unix_listener replication-notify { mode = 0666 user = vmail } } service auth { unix_listener exim-auth { group = Debian-exim mode = 0660 user = Debian-exim } } service config { unix_listener config { mode = 0666 user = vmail } } service doveadm { inet_listener { port = <some port or other> ssl = yes } } service imap-login { inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } } service lmtp { inet_listener lmtp { address = 127.0.0.1 port = <another port> } unix_listener lmtp { mode = 0666 } user = vmail } service managesieve-login { inet_listener sieve { port = <sieve port> } process_min_avail = 0 service_count = 1 vsz_limit = 64 M } service managesieve { process_limit = 100 } service replicator { process_min_avail = 1 unix_listener replicator-doveadm { mode = 0600 user = vmail } } ssl_cert =