/usr/share/help/es/evolution/mail-receiving-options-unix-mbox-spool-file.page is in evolution-common 3.18.5.2-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/help/es/evolution/../../../help-langpack/es/evolution/mail-receiving-options-unix-mbox-spool-file.page