[Dovecot] Purging a large folder... anything I need to be careful of?

Charles Marcus CMarcus at Media-Brokers.com
Wed Feb 10 14:16:41 EET 2010

On 2010-02-10 12:59 AM, Dennis Guhl wrote:
> Dave schrieb:
>> I've got a large message folder (about 40G in 'cur') that I need to
>> empty to a more reasonable size.  Oddly, my Thunderbird e-mail client
>> only sees about 2.4G of that, and has "looped" a few times.  What I
>> mean is, I thought someone was cleaning the folder out, but
>> Thunderbird apparently was actually just looping back to 0 every 4
>> gigs and starting to count up again  Ha.  But that's a sidenote.  So,
>> since Thunderbird 
> But it's a strange one.
> I have some fairly big folders (>>10G) too but there is no problem at
> all with TB

Not entirely accurate. TB does indeed have a big problem with mbox files
larger than 4GB. But as long as you don't set an IMAP folder that is
larger than 4GB to full offline mode, you should be fine, BUT... the
calculated size will be displayed using a 32-bit value, so as it
calculates the size, when it hits 4GB, it will roll over and start again
- so, a 6GB and a 10GB folder will both be displayed as 2GB...

>> apparently is not seeing all of the messages,

Yes it is - it is simply not calculating the folder size correctly. I
don't know if this an underlying OS issue (32-bit vs 64-bit), or a TB bug...

>> what is the safest way
>> to delete the files straight from the 'cur' folder?  IS that safe? 
>> Will I mess up any of the dovecot indexes in any way??
> Yes it is safe.
> Dovecot has self healing abilities which will fix the index files.

I don't think dovecots indexes are affected by this - it is merely a
cosmetic TB issue.


Best regards,


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