dsync does not like sieve

31 May 2026

      Hi,
I’m using Dovecot for many years. My installation is configured to manage
spam using sieve. In the same time, I have a backup server, connecting to
the main server every night in order to backup emails (note that the main
server is not pushing its data, but the backup server is pulling them).
Dovecot v2.4 made me re-write the configuration files, so maybe I missed
something, but since then, I cannot make both these service work in the
same time. With my current configuration, the backup server is terminating
in error with the following logs:
dsync-remote(example@example.com)<HbkSGoKQG2o8+gEAGKlOPA>: Error:
brain S: Exporting mailbox INBOX failed: Mailbox attribute iteration
failed: Internal error occurred. Refer to server log for more
information. [2026-05-31 03:36:03]
(and there are no more logs anywhere).
Because this message
<https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/MGCGR6B2HSEKPHS4LTM3JWD3LRECJZLB/#345N463ZJJU7MGEICA352KV6C4C4LUES>
was suggesting there could be a problem with sieve, I tried to modify the
configuration. And indeed, when changing sieve configuration, the backup is
working again. But then, my spam filter isn’t anymore.
Here are the relevant parts of the configuration for managing sieve. Can
someone help me saying what could be wrong?
protocols {
sieve = yes
imap = yes
lmtp = yes
}
sieve_extensions {
fileinto = yes
reject = yes
envelope = yes
encoded-character = yes
vacation = yes
subaddress = yes
comparator-i;ascii-numeric = yes
relational = yes
regex = yes
imap4flags = yes
copy = yes
include = yes
body = yes
variables = yes
enotify = yes
environment = yes
mailbox = yes
date = yes
index = yes
ihave = yes
duplicate = yes
mime = yes
foreverypart = yes
extracttext = yes
vnd.dovecot.pipe = yes
vnd.dovecot.environment = yes
}
sieve_pipe_bin_dir = /etc/dovecot/sieve
sieve_pipe_socket_dir = sieve-pipe
sieve_plugins {
sieve_imapsieve = yes
sieve_extprograms = yes
}
service managesieve-login {
inet_listener sieve {
port = 4190
}
}
sieve_script personal {
}
sieve_script default {
path = /etc/dovecot/sieve/spam.sieve
}
protocol imap {
mail_plugins {
acl = yes
quota = yes
imap_acl = yes
imap_quota = yes
imap_sieve = yes
}
}
protocol lmtp {
mail_plugins {
acl = yes
quota = yes
sieve = yes
}
}
namespace user {
inbox = yes
prefix =
separator = /
type = private
mailbox * {
sieve_script reportspam {
cause = flag
path = /etc/dovecot/sieve/report-spam.sieve
type = before
}
}
}
Thank you.
Stéphane
--
Bien cordialement, / Plej kore,
Stéphane Veyret
Hi,
I'm using Dovecot for many years. My installation is configured to manage
spam using sieve. In the same time, I have a backup server, connecting to
the main server every night in order to backup emails (note that the main
server is not pushing its data, but the backup server is pulling them).
Dovecot v2.4 made me re-write the configuration files, so maybe I missed
something, but since then, I cannot make both these service work in the
same time. With my current configuration, the backup server is terminating
in error with the following logs:
dsync-remote([1]example@example.com)<HbkSGoKQG2o8+gEAGKlOPA>: Error: brain S: Exporting mailbox INBOX failed: Mailbox attribute iteration failed: Internal error occurred. Refer to server log for more information. [2026-05-31 03:36:03]
(and there are no more logs anywhere).
Because [2]this message was suggesting there could be a problem with
sieve, I tried to modify the configuration. And indeed, when changing
sieve configuration, the backup is working again. But then, my spam filter
isn't anymore.
Here are the relevant parts of the configuration for managing sieve. Can
someone help me saying what could be wrong?
 protocols {
   sieve = yes
   imap = yes
   lmtp = yes
 }
 sieve_extensions {
   fileinto = yes
   reject = yes
   envelope = yes
   encoded-character = yes
   vacation = yes
   subaddress = yes
   comparator-i;ascii-numeric = yes
   relational = yes
   regex = yes
   imap4flags = yes
   copy = yes
   include = yes
   body = yes
   variables = yes
   enotify = yes
   environment = yes
   mailbox = yes
   date = yes
   index = yes
   ihave = yes
   duplicate = yes
   mime = yes
   foreverypart = yes
   extracttext = yes
   vnd.dovecot.pipe = yes
   vnd.dovecot.environment = yes
 }
 sieve_pipe_bin_dir = /etc/dovecot/sieve
 sieve_pipe_socket_dir = sieve-pipe
 sieve_plugins {
   sieve_imapsieve = yes
   sieve_extprograms = yes
 }
 service managesieve-login {
   inet_listener sieve {
     port = 4190
   }
 }
 sieve_script personal {
 }
 sieve_script default {
   path = /etc/dovecot/sieve/spam.sieve
 }
 protocol imap {
   mail_plugins {
     acl = yes
     quota = yes
     imap_acl = yes
     imap_quota = yes
     imap_sieve = yes
   }
 }
 protocol lmtp {
   mail_plugins {
     acl = yes
     quota = yes
     sieve = yes
   }
 }
 namespace user {
   inbox = yes
   prefix =
   separator = /
   type = private
   mailbox * {
     sieve_script reportspam {
       cause = flag
       path = /etc/dovecot/sieve/report-spam.sieve
       type = before
     }
   }
 }
Thank you.
Stephane
Bien cordialement, / Plej kore,
Stephane Veyret
References
Visible links

mailto:example@example.com
https://dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thread/MGCGR6...

Stéphane Veyret

Thank you. Stephane

Aki Tuomi

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