Being on KDE 4.9 on Kubuntu 12.04 I am quite happy with KMail/Kontact once more. Filters mainly work (they do go belly up now and then but nothing I can not deal with), lists/groups work and so on.

I have one gripe though: searching for mail/messages. It is showing far from the expected number of emails if I search for "internet" in "all folders" (believe me I have many mails on that subject). Same goes for other terms I know I use often in subject line.

I am kind of suspecting that Akonadi thinks it has done the indexing and all is good, seeing the number of upgrades I have done. Does anyone know if there is a way (apart from removing the database altogether) to instruct Akonadi to redo the job?

There are some pointers in that direction here in the "sticky topic" Akonadi and Nepomuk but no deeper explanation of the parameters:

viewtopic.php?f=215&t=98857

kind regards,
Sinclair

The "sticky" topic about Akonadi and Nepomuk lead me to look at a file
/HOME/.kde/share/config/akonadi_nepomuk_feederrc

I edited these lines to these values:
InitialIndexingComplete=false
and
DisableIdleDetection=true

the first one seems to advice the system indexing is done (it was set to true) and the second one to use CPU regardless of state (it was set to false).

Saved the file and did from konsole akonadictl stop, akondictl start.

Watched cpu getting crazy with virtuoso-t eating my CPU and let it take time.

Now searches on Subject, From, To etc takes a little bit time but seems accurate like in thousands of results in "from: anna" being 1 friend 1 colleague and several years of mails saved.

Now cpu has calmed down and the ......rc file states
InitialIndexingComplete=true

though I left it at the ....Detection=true

YMMV but for me now search seems working and accurate.

I have upgraded over the years so my "rc-files" are years and years old so this may only impact for those who upgrade and save their settings/data - if so I think it is a good pointer to the packagers that some files should be edited/deleted on upgrade