Abort IMAP COPY command from imapsieve?

10 Mar 2024


      Hi,
I'm finding myself regularly moving messages to the wrong folder in my
MUA. Most of the time this is easily corrected, but sometimes this is a
bit harder. Imagine selecting all messages in the 'Trash' or 'Junk'
folder, and moving them in the 'Archive' folder (by clicking on the
MUA's 'Archive' button in stead of the 'Delete' button).
I'm looking into blocking this server-side using an IMAPSieve script. So
far I've been able to log relevant details of such a message move, but I
don't how I can abort the message move altogether. I'm now using the
following config, which result in log messages like:
dovecot:
imap(tom@example.org)<540588><TmDbwVATNOoqEDeBFZcAASOvWpPsXcmR>: sieve:
DEBUG: move-to-archive: Message archived: mailbox-from=INBOX
mailbox-to=Archives.2023
message-id=648ab0b4-8439-4b2d-8e53-b97e700ff9d0@mail.example.org
subject='Testing IMAPSieve'
File: dovecot.conf
protocol imap {
mail_plugins = $mail_plugins imap_sieve
}
plugin {
sieve_plugins = sieve_imapsieve
sieve_implicit_extensions = +vnd.dovecot.debug
# Find out how to block messages from being from 'Trash' to 'Archive'
folder
imapsieve_mailbox1_name = Archives.*
#imapsieve_mailbox1_from = INBOX
imapsieve_mailbox1_before =
file:/etc/dovecot/sieve-scripts/move-to-archive.sieve
}
File: move-to-archive.sieve
require "environment";
require "variables";
require "vnd.dovecot.debug";
require "vnd.dovecot.imapsieve";
if header :matches "Message-ID" "*" {
set "message_id" "${1}";
} else {
set "message_id" "UNKNOWN";
}
if header :matches "Subject" "*" {
set "subject" "${1}";
} else {
set "subject" "UNKNOWN";
}
if environment :matches "vnd.dovecot.mailbox-from" "*" {
set "mailbox_from" "${1}";
} else {
set "mailbox_from" "UNKNOWN";
}
if environment :matches "vnd.dovecot.mailbox-to" "*" {
set "mailbox_to" "${1}";
} else {
set "mailbox_to" "UNKNOWN";
}
debug_log "move-to-archive: Message archived:
mailbox-from=${mailbox_from} mailbox-to=${mailbox_to}
message-id=${message_id} subject='${subject}'";
I tried the "reject" sieve command but that only works in the context of
delivery. Is there a way to abort the actual move, and return an error
to the MUA? Or am I on the wrong track altogether, and is there a better
approach?
NB: While doing research I found that not all environment variables in
RFC 6785 (https://www.rfc-editor.org/rfc/rfc6785.html#section-4) are
implemented in Pigeonhole? I tried to access the 'imap.cause' and
'imap.mailbox' variables but they were empty, only the variables from
RFC 5183 seem to be available. This is inline with the docs at
https://github.com/dovecot/pigeonhole/blob/main/README, but not with
https://github.com/dovecot/pigeonhole/blob/main/doc/plugins/imapsieve.txt
and
https://doc.dovecot.org/configuration_manual/sieve/plugins/imapsieve/,
which both seems to imply that RFC 6785 is implemented?
Kind regards,
Tom

Abort IMAP COPY command from imapsieve?

Tom Hendrikx

File: dovecot.conf

# Find out how to block messages from being from 'Trash' to 'Archive' folder imapsieve_mailbox1_name = Archives.* #imapsieve_mailbox1_from = INBOX imapsieve_mailbox1_before = file:/etc/dovecot/sieve-scripts/move-to-archive.sieve }

File: move-to-archive.sieve

debug_log "move-to-archive: Message archived: mailbox-from=${mailbox_from} mailbox-to=${mailbox_to} message-id=${message_id} subject='${subject}'";