Recovering expunged but not purged e-mails from mdbox with zlib compression
Yesterday I had to recover an e-mail which a user had deleted. If I understand this correctly the message was expunged but not purged (doveadm purge had not been run).
This e-mail was clearly still in the mdbox stored with zlib compression as I could tell using the doveadm dump command (doveadm dump -t dbox filename).
I could however not reveal the e-mail with the normal doveadm fetch -u username "body" guid (guid from dump output)
In the end I was able to recover the e-mail by cutting it out from the mdbox and running gunzip over it, but this method was very fiddly and would not have worked for a bulk job. I appreciate I could have just deleted the index files and gotten all the deleted messages back by having the index rebuilt but that would have been the proverbial "hammer to crack a nut".
Fortunately this e-mail had no attachment for me to worry about, as those are also detached for sis by dovecot.
Can anyone tell me of a quick and easy way to recover one or multiple e-mails marked as expunged but not purged which are stored in a mdbox with zlib compression? I'm sure I'll have to do this again the future and my method wouldn't work with a folder!
Clearly if I was not using zlib compression I could just have read the contents of the mdbox without any complication.
-- Daniel Schütze Director
CWA International Ltd 5th Floor, 42 Trinity Square London EC3N 4DJ
(t) + 44 (0)20 7242 8444 (e) dms@cwa.uk.com (w) http://www.cwa.international/
You can use mdbox_deleted driver to access mails with refcount 0. See https://wiki2.dovecot.org/MailboxFormat/dbox
Aki
On 10.11.2020 12.42, Daniel Schütze wrote:
Yesterday I had to recover an e-mail which a user had deleted. If I understand this correctly the message was expunged but not purged (doveadm purge had not been run).
This e-mail was clearly still in the mdbox stored with zlib compression as I could tell using the doveadm dump command (doveadm dump -t dbox filename).
I could however not reveal the e-mail with the normal doveadm fetch -u username "body" guid (guid from dump output)
In the end I was able to recover the e-mail by cutting it out from the mdbox and running gunzip over it, but this method was very fiddly and would not have worked for a bulk job. I appreciate I could have just deleted the index files and gotten all the deleted messages back by having the index rebuilt but that would have been the proverbial "hammer to crack a nut".
Fortunately this e-mail had no attachment for me to worry about, as those are also detached for sis by dovecot.
Can anyone tell me of a quick and easy way to recover one or multiple e-mails marked as expunged but not purged which are stored in a mdbox with zlib compression? I'm sure I'll have to do this again the future and my method wouldn't work with a folder!
Clearly if I was not using zlib compression I could just have read the contents of the mdbox without any complication.
-- Daniel Schütze Director
CWA International Ltd 5th Floor, 42 Trinity Square London EC3N 4DJ
(t) + 44 (0)20 7242 8444 (e) dms@cwa.uk.com (w) http://www.cwa.international/
Dear Aki
Thank you. Unfortunately I'm struggling to get the right syntax for this as it looks like someone else was here too
https://dovecot.org/pipermail/dovecot/2018-July/112441.html
The location in my dovecot.conf is
mdbox:%%h/mdbox:INDEX=/indexdisk/indexes/%%n:INDEXPVT=~/mdbox/shared/%%n
I'm trying to fetch a message (for testing purposes now) based on it's guid as that is available from doveadm dump.
So my syntax is (based on the previous person who didn't get it to work).
doveadm -o "mail_location=mdbox_deleted:%%h/mdbox:INDEX=/indexdisk/indexes/%%n:INDEXPVT=~/mdbox/shared/%%n" fetch "body" guid (msg.guid from doveadm dump)
But that's getting no response. I've tried putting in the hard path in case there is any trouble with the %%h etc but that doesn't help either.
I've also tried the fetch with the subject of a known deleted message and also adding mailbox Drafts (as I know that's where it is or rather was) but to no avail.
Given doveadm dump gives msg.uid and no subject I'd prefer to use that in any case.
There are no error messages, I do with doveadm was a little more verbose to help over these bumps!
Any chance of a helping hand?
Daniel Schütze Director
CWA International Ltd 5th Floor, 42 Trinity Square London EC3N 4DJ
(t) + 44 (0)20 7242 8444 (e) dms@cwa.uk.com (w) http://www.cwa.international/ On 10/11/20 10:53, Aki Tuomi wrote:
You can use mdbox_deleted driver to access mails with refcount 0. See https://wiki2.dovecot.org/MailboxFormat/dbox
Aki
On 10.11.2020 12.42, Daniel Schütze wrote:
Yesterday I had to recover an e-mail which a user had deleted. If I understand this correctly the message was expunged but not purged (doveadm purge had not been run).
This e-mail was clearly still in the mdbox stored with zlib compression as I could tell using the doveadm dump command (doveadm dump -t dbox filename).
I could however not reveal the e-mail with the normal doveadm fetch -u username "body" guid (guid from dump output)
In the end I was able to recover the e-mail by cutting it out from the mdbox and running gunzip over it, but this method was very fiddly and would not have worked for a bulk job. I appreciate I could have just deleted the index files and gotten all the deleted messages back by having the index rebuilt but that would have been the proverbial "hammer to crack a nut".
Fortunately this e-mail had no attachment for me to worry about, as those are also detached for sis by dovecot.
Can anyone tell me of a quick and easy way to recover one or multiple e-mails marked as expunged but not purged which are stored in a mdbox with zlib compression? I'm sure I'll have to do this again the future and my method wouldn't work with a folder!
Clearly if I was not using zlib compression I could just have read the contents of the mdbox without any complication.
-- Daniel Schütze Director
CWA International Ltd 5th Floor, 42 Trinity Square London EC3N 4DJ
(t) + 44 (0)20 7242 8444 (e) dms@cwa.uk.com (w) http://www.cwa.international/
participants (2)
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Aki Tuomi
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Daniel Schütze