/usr/share/kservices5/ is in kmail 4:16.04.3-4~deb9u1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/kservices5/ServiceMenus/
/usr/share/kservices5/ServiceMenus/kmail_addattachmentservicemenu.desktop
/usr/share/kservices5/kcm_kpimidentities.desktop
/usr/share/kservices5/kcmkmailsummary.desktop
/usr/share/kservices5/kmail_config_accounts.desktop
/usr/share/kservices5/kmail_config_appearance.desktop
/usr/share/kservices5/kmail_config_composer.desktop
/usr/share/kservices5/kmail_config_identity.desktop
/usr/share/kservices5/kmail_config_misc.desktop
/usr/share/kservices5/kmail_config_security.desktop
/usr/share/kservices5/kontact/
/usr/share/kservices5/kontact/kmailplugin.desktop