How to eliminate writing the duplicate delivery database ?

Eric Luyten Eric.Luyten at
Fri Apr 24 10:39:46 EDT 2009

On Fri, April 24, 2009 4:17 pm, Michael Menge wrote:
> Quoting Eric Luyten <Eric.Luyten at>:
>> A couple weeks ago, in order to accommodate local users (not) receiving
>>  mail messages written by some Outlook/Exchange correspondants
>> (Message-Id
>> gets re-used...) I disabled Cyrus duplicate suppression by adding the
>> following line to my imapd.conf :
>> duplicatesuppression: 0
>> Somewhat naively I thought that Cyrus wouldn't be writing the duplicate
>>  delivery database anymore, but this is not the case.
> Cyrus still needs to write to the delivery database, e.g. for vacation
> messages.


Thank you for bringing this to my attention !
(we're not using Sieve's vacation function, but that's another issue)

> But it will deliver messages even if they have the same message-id.

Correct. My configuration change had the desired effect.

>> Is there, other than by patching the C code, a way to
>> disabling writing delivery.db ?
> Why do you want do disable writing to the delivery.db?

It seemed like a lot of DB updates we could get rid of.
We're still with a Cyrus monolith (a single mailboxes.db
and deliver.db with far more writes to deliver.db, mailbox
creations and removals numbering only a few dozen a day,
while message deliveries can run into ten to twenty per

On the partition where both databases reside we observe
double the amount of writes compare to any of the eight
message spools.

Eric Luyten, Computing Centre VUB/ULB.

More information about the Info-cyrus mailing list