/usr/include/KF5/ is in libkf5akonadimime-dev 4:15.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/KF5/Akonadi/
/usr/include/KF5/Akonadi/KMime/
/usr/include/KF5/Akonadi/KMime/AddressAttribute
/usr/include/KF5/Akonadi/KMime/CommandBase
/usr/include/KF5/Akonadi/KMime/MarkAsCommand
/usr/include/KF5/Akonadi/KMime/MessageFlags
/usr/include/KF5/Akonadi/KMime/MessageFolderAttribute
/usr/include/KF5/Akonadi/KMime/MessageModel
/usr/include/KF5/Akonadi/KMime/MessageParts
/usr/include/KF5/Akonadi/KMime/MessageStatus
/usr/include/KF5/Akonadi/KMime/MoveCommand
/usr/include/KF5/Akonadi/KMime/RemoveDuplicatesJob
/usr/include/KF5/Akonadi/KMime/SpecialMailCollections
/usr/include/KF5/Akonadi/KMime/SpecialMailCollectionsDiscoveryJob
/usr/include/KF5/Akonadi/KMime/SpecialMailCollectionsRequestJob
/usr/include/KF5/Akonadi/KMime/StandardMailActionManager
/usr/include/KF5/akonadi/
/usr/include/KF5/akonadi-mime_version.h
/usr/include/KF5/akonadi/kmime/
/usr/include/KF5/akonadi/kmime/addressattribute.h
/usr/include/KF5/akonadi/kmime/akonadi-mime_export.h
/usr/include/KF5/akonadi/kmime/commandbase.h
/usr/include/KF5/akonadi/kmime/markascommand.h
/usr/include/KF5/akonadi/kmime/messageflags.h
/usr/include/KF5/akonadi/kmime/messagefolderattribute.h
/usr/include/KF5/akonadi/kmime/messagemodel.h
/usr/include/KF5/akonadi/kmime/messageparts.h
/usr/include/KF5/akonadi/kmime/messagestatus.h
/usr/include/KF5/akonadi/kmime/movecommand.h
/usr/include/KF5/akonadi/kmime/removeduplicatesjob.h
/usr/include/KF5/akonadi/kmime/specialmailcollections.h
/usr/include/KF5/akonadi/kmime/specialmailcollectionsdiscoveryjob.h
/usr/include/KF5/akonadi/kmime/specialmailcollectionsrequestjob.h
/usr/include/KF5/akonadi/kmime/standardmailactionmanager.h