ok duplicsate emails (even across dsync, replication etc) is typically handled via a global sieve script

I use :

# cat duplicates.sieve require "duplicate"; # for dovecot >= 2.2.18

if duplicate { discard; stop; }

for the scripts

and setup sieve to work via my dovecot.conf file

relative parts below :

protocols = imap pop3 lmtp sieve

protocol lmtp { mail_plugins = $mail_plugins sieve postmaster_address = monitor@scom.ca }

protocol lda { mail_plugins = $mail_plugins sieve }

plugin { .....

sieve = file:~/sieve;active=~/sieve/.dovecot.sieve

sieve_duplicate_default_period = 1h sieve_duplicate_max_period = 1d sieve_extensions = +duplicate +notify +imapflags +vacation-seconds sieve_global_dir = /usr/local/etc/dovecot/sieve sieve_before = /usr/local/etc/dovecot/sieve/duplicates.sieve

..... }

service managesieve-login { process_limit = 1000 vsz_limit = 1g inet_listener sieve { port = 4190 } }

protocol sieve { managesieve_implementation_string = Dovecot Pigeonhole managesieve_max_line_length = 65536 }

note the sieve_before which handles duplictes during delivery etc.

Happy Monday !!! Thanks - paul

Paul Kudla

Scom.ca Internet Services http://www.scom.ca 004-1009 Byron Street South Whitby, Ontario - Canada L1N 4S3

Toronto 416.642.7266 Main 1.866.411.7266 Fax 1.888.892.7266

On 5/15/2022 12:38 PM, Thom Pol wrote:

Hi,

Hope you are well.

We have a cluster of 2 Dovecot servers, both on v2.3.13 (89f716dc2), using dsync to sync the messages between them.

Previously, we used TCPS to sync the messages, but after some testing, we concluded that syncing over SSH resulted in a lot less failed syncs, so we started using SSH.

The change has been a success, but I now notice a issue when a email client immediately moves a messages to a separate folder while Dovecot is syncing, where the message is seen twice in the folder (with the exact same headers/content).

For example, I have set a filter in my email client, Thunderbird, to immediately move all emails coming from this list to a separate folder. When opening that folder, I do not see one, but two unread messages, both identical to each other.

When checking the directories on the server, I see this: mx1: /var/vmail/example.com/joe/Maildir/.Subdir.Subdir/cur/1652615808.M190190P990486.mx2,S=19089,W=19384:2,S /var/vmail/example.com/joe/Maildir/.Subdir.Subdir/cur/1652615811.M180050P1376677.mx1,S=19089,W=19384:2,S

mx2: /var/vmail/example.com/joe/Maildir/.Subdir.Subdir/cur/1652615811.M981426P990530.mx2,S=19089,W=19384:2,S /var/vmail/example.com/joe/Maildir/.Subdir.Subdir/cur/1652615808.M190190P990486.mx2,S=19089,W=19384:2,S

Note the difference: on mx1, one indicates mx1, and one mx2, while on the other server, both indicate mx2/

Any idea (other then telling end-users not to use such filters) how we could prevent these duplicate messages?

This is our config: # Pigeonhole version 0.5.13 (cdd19fe3) # OS: Linux 5.10.0-13-cloud-amd64 x86_64 Debian 11.3 # Hostname: mx1.example.com auth_mechanisms = plain login disable_plaintext_auth = no dsync_remote_cmd = ssh -p 222 -l%{login} %{host} doveadm dsync-server -u%u imap_capability = +SPECIAL-USE XLIST listen = *,[::] lmtp_rcpt_check_quota = yes log_timestamp = "%Y-%m-%d %H:%M:%S " mail_max_userip_connections = 100 mail_plugins = quota mail_privileged_group = vmail 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 = separator = . } passdb { args = /etc/dovecot/dovecot-sql.conf driver = sql } plugin { mail_replica = remote:root@mx2.example.com quota = dict:user::file:/var/vmail/%d/%n/.quotausage quota_status_nouser = DUNNO quota_status_overquota = 552 5.2.2 Mailbox is full quota_status_success = DUNNO sieve = /var/vmail/%d/%n/.sieve sieve_after = /var/vmail/%d/%n/.ispconfig.sieve sieve_before = /var/vmail/%d/%n/.ispconfig-before.sieve sieve_max_actions = 100 sieve_max_redirects = 25 sieve_max_script_size = 2M } protocols = imap pop3 lmtp replication_max_conns = 50 service aggregator { fifo_listener replication-notify-fifo { mode = 0666 user = vmail } unix_listener replication-notify { mode = 0666 user = vmail } } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } unix_listener auth-userdb { group = vmail mode = 0600 user = vmail } user = root } service imap-login { client_limit = 1000 process_limit = 512 } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } service quota-status { client_limit = 1 executable = quota-status -p postfix unix_listener /var/spool/postfix/private/quota-status { group = postfix mode = 0660 user = postfix } } service replicator { process_min_avail = 1 unix_listener replicator-doveadm { mode = 0666 user = vmail } } service stats { unix_listener stats-reader { group = vmail mode = 0660 user = vmail } unix_listener stats-writer { group = vmail mode = 0660 user = vmail } } ssl_cert =

Thanks in advance for your thoughts.

Kind regards,

Thom Pol

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