I made a fresh install of mageia to the cauldron after reinstalling mageia6.

(the root partition was formated, not the home, but I rename the previous user folder, and "recreate" a new user with the same name as previously. I did'nt copy past the content of the configuration folders located in the previous user directory.)

Before I export my gpg keys with kleopatra, and tried to import with kleopatra. It did, but shows errors. Kleopatra said "wrong format".
But it was imported. I configure Kmail, it creates a new wallet in kwallet, it was able to download all mails, but wasn't able to decrypt them, when clicking on the key ID, kleopatra shown error wrong format. I decided to use Kgpg, it wasn't installed by default, I install it, and without anyconfiguration works well with the imported keys from kleopatra. Better ! When I compare them both, Kleopatra was unable to change the passphrase of the key, but Kgpg do it.
I tried to remove kleopatra. But kmail stays block and without errors, says that I don't have any key manager. I can not communicate with Kgpg.

Today I start my laptop, now kmail is enable to open the kwallet so it can not recover the password of the mail account (approximative translation to english :) "Error while trying to decrypt the wallet kdewallet with the help of GPG. If you use a pincard, check if it is well plugged then try again. Error GPG, wrong passphrase." It makes a loop asking with "retry", and abord with "Cancel". But after canceling, it asks me again my mail account password, after validating the password, come back to the same error "Error while trying to decrypt the wallet kdewallet..."

I'm currently enable to read encrypted mail and using the keys graphically.
I tried to remove kwallet, kleopatra, kmail and their libraries, but their remember the whole configuration.

Is it possible to mrproper the configuration of kwallet kmail kleopatra and co, to retry from the beginning ?
Is there a way to precise which key manager to use for Kmail (Kgpg instead of Kleopatra) ?

List of software removed and reinstalled :
kleopatra-17.12.2-1.mga7.x86_64.rpm
kleopatra-handbook-17.12.2-1.mga7.noarch.rpm
kmailtransport-17.12.2-1.mga7.x86_64.rpm
kmail-17.12.2-1.mga7.x86_64.rpm
kmail-handbook-17.12.2-1.mga7.noarch.rpm
kmail-account-wizard-17.12.2-1.mga7.x86_64.rpm
* kmailtransport-handbook-16.12.3-1.mga6.noarch
kwallet-5.42.0-1.mga7.x86_64.rpm

lib64kf5kleopatraclientcore1-17.12.2-1.mga7.x86_64.rpm
lib64kf5kleopatraclientgui1-17.12.2-1.mga7.x86_64.rpm
lib64kmailprivate5-17.12.2-1.mga7.x86_64.rpm

I cannot reinstall kmailtransport-handbook-16.12.3-1.mga6.noarch, it isn't in the mga7 repo. I don't know if it is important, or useless, but if it was useless, it won't be packaged ^^