Re: Lazy-Expunge plugin documentation incomplete?

4 Sep 2026

      Thank you!  This is tremendeously helpful, and now the messages that 
users delete are moved, however...
The problem now is that the folders are lost, so recovering from 
mass deletions loses folder hierarchy (in Dovecot 2.3 the folder
structure was always preserved, which is important when helping users
recover messages that they accidentally deleted, or their AI bots
deleted, or the rare occurance when Outlook goes on one of its crazy
mass-deletion rampages, etc.).
I haven't been able to find anything about preserving mailbox 
folders in the documentation for Dovecot 2.4.1 -- is there a setting
I'm missing that preserves folder structure within my
~/Maildir.deleted/ path?  (Our mailbox path setting ~/Maildir/ and we
prefer keeping lazy-expunge files in ~/Maildir.deleted/ for each
user, respectively.)
Here is my current working configuration file (on our test servers 
for now as I continue to work on this), which doesn't preserve
deletions in their respective mailbox folders...
-------- BEGIN: 16-lazy-expunge.conf --------
lazy_expunge_mailbox = EXPUNGED/INBOX
lazy_expunge_only_last_instance = yes
namespace inbox {
mailbox EXPUNGED {
autoexpunge = 32days
autoexpunge_max_mails = 100000
}
acl owner {
rights = rwstipekxa
}
mailbox \Drafts {
lazy_expunge_mailbox =
}
}
namespace lazy_expunge_ns {
hidden = yes
list = no
prefix = EXPUNGED/
subscriptions = no
separator = /
#location = maildir:~/Maildir.deleted:INDEX=
mail_driver = maildir
mail_path = ~/Maildir.deleted
mail_index_path =
mail_index_private_path =
mail_cache_path =
mailbox EXPUNGED {
quota_ignore = yes
}
}
mail_plugins {
lazy_expunge = yes
}
-------- END: 16-lazy-expunge.conf --------
While most deleted messages show up under "Deleted Items" or "Trash" 
because a lot of eMail software moves deletions there first, there
are many instances where this doesn't occur, and deletion occurs
directly -- some webmail clients do this, or the user deletes a
folder that was moved to their Trash folder, or they held down the
Alt or CTRL key when deleting messages (to bypass the Trash folder
move), or a script/rule deletes directly, etc.
...
2026-06-17T10:13:27.138080-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Error: Mailbox Deleted Items: UID 864: lazy_expunge: Couldn't open expunge mailbox: Failed to open mailbox EXPUNGED/: Invalid mailbox name 'EXPUNGED/': Ends with hierarchy separator
You notice that it speaks about mailbox, not namespace. Try using EXPUNGED/INBOX as lazy_expunge_mailbox. You are now pointing it to a namespace.
Aki
...
On 17/06/2026 20:26 EEST Randolf Richardson via dovecot <dovecot@dovecot.org> wrote:
Thank you for your help, I appreciate it very much.
What I meant by "not working" is that the deleted messages were just
disappearing, without being placed in the ~/Maildir.deleted/ folder
(which is the expected behaviour), and with no errors being logged.
I tried replacing my 16-lazy-expunge.conf file with what you
provided, and now, upon deletion, the IMAP4 client (Evolution on
Linux in this case) reports an "expunge" operation error.  The
following errors now show up in the logs (this is on a test server
that worked correctly before upgrading from 2.3 to 2.4.1):
2026-06-17T10:13:27.137678-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox Deleted Items: UID 864: Mail metadata accessed
2026-06-17T10:13:27.137908-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox EXPUNGED/: Mailbox opened
2026-06-17T10:13:27.138080-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Error: Mailbox Deleted Items: UID 864: lazy_expunge: Couldn't open expunge mailbox: Failed to open mailbox EXPUNGED/: Invalid mailbox name 'EXPUNGED/': Ends with hierarchy separator
2026-06-17T10:13:27.138259-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox Deleted Items: UID 864: Expunge requested
2026-06-17T10:13:27.138422-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox Deleted Items: UID 865: Expunge requested
2026-06-17T10:13:27.138547-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox Deleted Items: UID 866: Expunge requested
2026-06-17T10:13:27.138682-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox Deleted Items: UID 867: Expunge requested
2026-06-17T10:13:27.138807-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Debug: Mailbox Deleted Items: UID 868: Expunge requested
2026-06-17T10:13:27.138919-07:00 mail02 dovecot: imap(nobody@example.com)<1232591><CUPOK3ZUdOIKAQHB>: Error: Mailbox Deleted Items: Lazy-expunge transaction failed: Mailbox Deleted Items: UID 864: lazy_expunge: Couldn't open expunge mailbox: Failed to open mailbox EXPUNGED/: Invalid mailbox name 'EXPUNGED/': Ends with hierarchy separator
I did attempt removing the trailing slash, but the errors logged
remained the same.
I also tried to add the following lines to "mailbox EXPUNGED" stanza
(which is what I will be needing, although I'm unsure if this is the
correct placement), which resulted in more errors that I think I
should ignore at this point until the errors (above) are sorted:
mail_driver = maildir
mail_path = ~/Maildir.deleted
mail_index_private_path = 
mail_cache_path = 
Note:  Some eMail clients delete directly instead of moving messages
to the "Deleted Items" (Trash) folders, and Dovecot 2.3 preserved
this structure with its lazy-expunge configuration (which is a
wonderfully helpful feature), which is all stored in the specified
"mail_path" file system hierarchy separate from the user's mailbox.
Thanks!
...
For 2.4 you would use
acl_driver = vfile
acl_global_path = /etc/dovecot/dovecot.acl
lazy_expunge_mailbox = EXPUNGED/
lazy_expunge_only_last_instance = yes
namespace inbox {
mailbox EXPUNGED {
autoexpunge = 32days
autoexpunge_max_mails = 100000
}
mailbox \Drafts {
lazy_expunge_mailbox =
}
}
namespace ns {
hidden = yes
list = no
prefix = EXPUNGED/
subscriptions = no
mailbox EXPUNGED {
quota_ignore = yes
}
}
mail_plugins {
acl = yes
lazy_expunge = yes
}
but you never did explain "how it does not work".
Aki
...
On 15/06/2026 19:17 EEST Randolf Richardson via dovecot <dovecot@dovecot.org> wrote:
One of the Dovecot repository maintainers on GitHub recommended
sending an eMail to you regarding the issue I encountered:
Documentation for lazy-expunge doesn't work
https://github.com/dovecot/documentation/issues/1555

I converted from Dovecot 2.3 to Dovecot 2.4.1, which was not a minor
upgrade. Anyway, I can't get the lazy-expunge plugin to work in 2.4.1
now. Here's my configuration file from 2.3 -- how can I get this
working in 2.4.1? Thanks.
namespace inbox {
mailbox EXPUNGED {
autoexpunge = 32days
autoexpunge_max_mails = 100000
#auto = create
}
}
Namespace for lazy_expunge plugin
namespace {
prefix = EXPUNGED/
hidden = yes
list = no
subscriptions = no
separator = /
location = maildir:~/Maildir.deleted:INDEX=
}
mail_plugins = $mail_plugins lazy_expunge acl
plugin {
Move expunged messages into the .EXPUNGED namespace
lazy_expunge = EXPUNGED/
Only move to expunged storage if this is the last copy of the
message in the user´s account
lazy_expunge_only_last_instance = yes
Exclude Drafts from lazy expunging
lazy_expunge_exclude = \Drafts
Copy of each message is done with hard links whenever possible
maildir_copy_with_hardlinks = yes
Define ACL so that user cannot list the .EXPUNGED mailbox
Example entry:  .EXPUNGED owner rwstipekxa
acl = vfile:/etc/dovecot/dovecot.acl
dovecot.acl contains one line:  EXPUNGED owner ip
Expunged messages most likely don't want to be included in quota:
quota_rule = EXPUNGED:ignore
}
#lazy_expunge_mailbox = EXPUNGED
Here's an example of someone else who encountered the same problem:
https://www.dovecot.org/mailman3/archives/list/dovecot@dovecot.org/thr
ead/25BXSHQWGQQ3ACVZSYF3O3LC4WROTUCI/
Randolf Richardson, CNA - randolf@inter-corporate.com
Inter-Corporate Computer & Network Services, Inc.
Beautiful British Columbia, Canada
https://www.inter-corporate.com/

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Randolf Richardson, CNA - randolf@inter-corporate.com
Inter-Corporate Computer & Network Services, Inc.
Beautiful British Columbia, Canada
https://www.inter-corporate.com/