[Dovecot] Many messages clustered around the same date.saved value

[Timo Sirainen]

On 29.3.2012, at 5.41, Joseph Tam wrote:

>> Ah, with mbox there isn't any usable fallback for date.saved.  If it's
>> not in dovecot.index.cache, the current time is used.
> 
> I'm a little confused as to why it needed a fallback.  In other words,
> why wasn't date.saved put into the index as soon as the IMAP operation
> copied it into "Trash"?
> 
> If this data isn't set at that time, when does it get instantiated?
> When I actually ask for it?


Well..:

 - date.saved is stored only in dovecot.index.cache file
 - if it doesn't exist and is requested, the current time is returned and it's added to the cache
 - when date.saved has already fetched once (so it already exists in dovecot.index.cache file), and mail is saved via LDA/IMAP then it gets added there immediately when saving
 - dovecot.index.cache has caching decisions, and some old/unused fields may get dropped from it once in a while
 - maybe due to some bugs or whatever, the fields or the entire cache may get dropped for some other reason

So it probably should have worked, but for some reason didn't.

It would be possible to store date.saved in dovecot.index file, like mdbox does, so cache decisions wouldn't matter. But probably too much trouble to be worth it, very few mbox installations care about it.