/usr/include/KF5/Akonadi/ is in libkf5akonadimime-dev 4:16.04.2-2.
This file is owned by root:root, with mode 0o755.
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/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