cyrus-imap 2.5.3 - `lost' messages

Michael Menge michael.menge at
Tue Aug 14 03:38:09 EDT 2018

Quoting Dirk-Willem van Gulik <dirkx at>:

> On a smal cyrus imap 2.5.3 setup (freebsd ports, default settings,  
> 5k users, 300 Gb mboxes) we are seeing very sporadic `loss' of  
> messages (once every few months; 1 or 2 messages; out of a few 100k  
> to a million going through perfectly fine in the same period).
> They disappear; but are still present as a /var/spool/imap/user/X/12345.
>  files.
> But cannot be found; even when searching through IMAP on message-ID  
> or otherwise unique elements. Searches in the same veign for the  
> messages before/after the lost one work and return those.
> A grep through the cyrus.index shows its unique message ID.
> A full  reconstruct with /-r/-R/-G does not seem to bring it back as visible.
> The mesaages lost are otherwise normal; fully valid mime; and when
> re-injected - pass through and surface.
> What is the right way to debug this ? We suspect it may have  
> something to do with either (al)pine and thunderbird; as it seems to  
> hit users that mix those two clients - during periods they use both.  
> All else seems normal.

Do you use delayed expunge mode (man imapd.conf see expunge_mode)?
If yes, "unexpunge -l user/X" will show you the mails that have been  
deleted but are still on the disk.
You will also see the time the mail was deleted.


    Michael Menge

M.Menge                                Tel.: (49) 7071/29-70316
Universität Tübingen                   Fax.: (49) 7071/29-5912
Zentrum für Datenverarbeitung          mail:  
michael.menge at
Wächterstraße 76
72074 Tübingen

More information about the Cyrus-devel mailing list