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