/usr/include/evolution-data-server/ews/ is in evolution-ews 3.18.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/evolution-data-server/ews/e-ews-connection-utils.h
/usr/include/evolution-data-server/ews/e-ews-connection.h
/usr/include/evolution-data-server/ews/e-ews-debug.h
/usr/include/evolution-data-server/ews/e-ews-enums.h
/usr/include/evolution-data-server/ews/e-ews-enumtypes.h
/usr/include/evolution-data-server/ews/e-ews-folder.h
/usr/include/evolution-data-server/ews/e-ews-item-change.h
/usr/include/evolution-data-server/ews/e-ews-item.h
/usr/include/evolution-data-server/ews/e-ews-message.h
/usr/include/evolution-data-server/ews/e-ews-notification.h
/usr/include/evolution-data-server/ews/e-ews-oof-settings.h
/usr/include/evolution-data-server/ews/ews-errors.h