/usr/include/GNUstep/SOGo is in sogo 2.2.17a-1.1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/include/GNUstep/../../lib/GNUstep/Frameworks/SOGo.framework/Headers
/usr/include/GNUstep/../../lib/GNUstep/Frameworks/SOGo.framework/Headers