Deleting and Undeleting Messages and Folders

Terminology & Definitions

This section clarifies some of the subtle nuances between delete, expunge and expire in different contexts, used throughout this chapter.

Message context


sets the \Deleted flag on the message using STORE +Flags \Deleted via IMAP client


delete messages from the cyrus folder index that have the \Deleted flag set using EXPUNGE via IMAP client. With expunge_mode: delayed, this doesn’t delete the file from the filesystem.


recover messages into the cyrus folder index based on filesystem content (only possible with expunge_mode: delayed)


remove the \Deleted flag on the message using STORE -Flags \Deleted via IMAP client.

Folder context


deletes the folder and all messages inside it using DELETE via IMAP client. If using delete_mode: delayed, this renames the folder, rather than deletes the folder, as discussed below.

Otherwise, the folder and messages are removed from the mailbox list and the filesystem.


rename the deleted folder back to the original location using renamemailbox in cyradm.

Expiring Deleted Messages and Folders

In the EVENTS block of cyrus.conf, you should have a line similar to the following:

delprune  cmd="cyr_expire -E 1 -D 7 -X 7 -a" at=2300

-D 7

permanently deletes from the filesystem mailboxes and folders that were deleted more than 7 days ago.

-E 1

prunes entries older than 1 day from the duplicate delivery suppression database.

-X 7

permanently deletes from the filesystem expunged messages that were expunged more than 7 days ago.

To use delayed deletion of mailboxes, you need the following entry in imapd.conf(5):

delete_mode: delayed

New in version 2.3.9.

The default prefix for deleted mailboxes is DELETED but it probably doesn’t hurt to specify it in imapd.conf(5) as well:

deletedprefix: DELETED

New in version 2.3.9.

Undeleting Folders

The following assumes that you are using the UNIX hierarchy separator. If it’s off then replace ‘/’ in the names with ‘.’

With the previous configuration options in place, whenever a mail folder or mailbox is deleted, it will be renamed to DELETED/mailfoldername/4D5C6B7A where 4D5C6B7A is a hex-encoded timestamp and DELETED is the prefix for deleted mailboxes.

4D5C6B7A can be converted back to a human-readable time using a simple one-liner in Perl:

$ perl -le 'print scalar(localtime(hex("4D5C6B7A")));'
Thu Feb 17 00:27:38 2011


The ACL on the deleted folder remains the same so undeleting it is as simple as renaming it as a sub-folder of the recreated mailbox or back to the original folder name depending on whether the mailbox has been recreated or not. If you have to add an ACL to be able to delete the mailbox, you may wish to remove the ACL after the undelete has been finished.

The following examples assume a mailbox for has been deleted:

cyradm> listmailbox user/john*

If there’s no output from the above command, the mailbox has not been recreated since being deleted and you can rename the mailbox and any folders back to the original name as follows. If the mailbox has been recreated, you will probably want to rename the deleted folders into a subfolder of the new mailbox, for example user/john/ becomes user/john/ and user/john/Sent/ becomes user/john/restored/

In either case the commands are similar but with the latter option you need to insert the extra “/restored” after the user/john:

cyradm> listmailbox DELETED/user/john*
DELETED/user/john/ (HasNoChildren)
DELETED/user/john/Drafts/ (HasNoChildren)
DELETED/user/john/Sent/ (HasNoChildren)
DELETED/user/john/Trash/ (HasNoChildren)
cyradm> renamemailbox DELETED/user/john/ user/
cyradm> renamemailbox DELETED/user/john/Drafts/ user/john/
cyradm> renamemailbox DELETED/user/john/Sent/ user/john/
cyradm> renamemailbox DELETED/user/john/Trash/ user/john/

Unfortunately there’s no easy way to rename the entire mailbox back including all the subfolders and the hex timestamp can vary between folders in the same mailbox if it was a mailbox with some large folders.

This is because it’s the time that particular folder was deleted, not when the first folder was deleted.

Recursively undeleting a mailbox and all subfolders:

Undeleting messages in a mailbox

The following examples assume you have an installation of cyrus where there are binaries in /usr/lib/cyrus-imapd/ - if not, adjust path to suit.

List messages available to unexpunge:

# /usr/lib/cyrus-imapd/unexpunge -l user/

Each message will give you something like the following:

UID: 11422
    Size: 7786
    Sent: Mon Mar 10 12:00:00 2014
    Recv: Mon Mar 10 16:06:32 2014
    Expg: Mon Mar 10 16:53:55 2014
    From: john doe <>
    To  : <>
    Cc  :
    Bcc :
    Subj: {44}
re: some random subject of length 44 chars."

To unexpunge a single message:

# /usr/lib/cyrus-imapd/unexpunge -udv user/ 11422
restoring expunged messages in mailbox 'user/'
Unexpunged user/ 11422 => 11438
restored 1 expunged messages

To unexpunge all the messages and mark them as undeleted as well:

# /usr/lib/cyrus-imapd/unexpunge -adv user/


This isn’t recursive. It will only restore the messages in the folder specified.

To find other folders, ctl_mboxlist can be used.

# /usr/lib/cyrus-imapd/ctl_mboxlist -d | grep!user.john    0 default   lrswipkxtecda!user.john.Lists  0 default   lrswipkxtecda!user.john.Lists.cyrus    0 default   lrswipkxtecda!user.john.Deleted Messages   0 default   lrswipkxtecda

Run the unexpunge command for every folder that needs to have mail undeleted.

For folder names that have spaces ‘ ‘, the spaces need to be escaped with a backslash.

# /usr/lib/cyrus-imapd/unexpunge -adv user/john/