/usr/lib/ghc-doc/hoogle/libghc-smtp-mail-doc.txt is in libghc-smtp-mail-doc 0.1.4.6-1build2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-smtp-mail-doc/html/smtp-mail.txt