kontakt chrashes by using kmail every time whatever I do

using kontact the kmail app broke several times. if i lick to another account then again. if i using html from a secure mail kontact collapse again. It is not nice to open the app several times for reading mail again and again.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: kmail 4:17.12.3-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-23.25-generic 4.15.18
Uname: Linux 4.15.0-23-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: KDE
Date: Fri Jun 15 18:53:57 2018
InstallationDate: Installed on 2018-05-28 (18 days ago)
InstallationMedia: Kubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: kmail
UpgradeStatus: No upgrade log present (probably fresh install)