cyrus and 500k to >1M mails per inbox

Derek Yarnell derek at
Fri Feb 12 00:55:38 EST 2010

On 2/11/10 10:23 AM, Carsten Hoeger wrote:
> Hi,
> we have a customer running cyrus imap on RHEL5 cluster with a few thousand
> mailboxes.
> Every single mail is sent to a second host acting as a read-only archive (all
> imap acls set to no write access).
> The plan is, that all mail on that second host is kept for a long time.
> After some years, old mail will be purged automatically.
> It's quite likely, that these mailboxes will grow to 500000 or even more then
> 1M mails per mailbox.
> Does anybody have experience with such big mailboxes?
> The filesystem is LVM with ext3.


Just as an aside we archive our root mail (lots of crap) into a cyrus 
mailbox and found that past 250k messages it just began to suck at the 
client layer.

What we did was have sieve filter that would be re-generated on a 
monthly basis (using sievec) in the account that would filter into a 
folder for that month.  The only thing was that you would have to 
pre-populate the folders (or maybe I am a sieve noob and not aware of a 
way that sieve can create the folder if it doesn't exist).

Anyway this is a pretty good way to deal with large archival mailboxes.


Derek T. Yarnell
University of Maryland
Institute for Advanced Computer Studies

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