/usr/share/php/Horde/ is in php-horde-mail-autoconfig 1.0.2-3ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/Horde/Mail/
/usr/share/php/Horde/Mail/Autoconfig/
/usr/share/php/Horde/Mail/Autoconfig.php
/usr/share/php/Horde/Mail/Autoconfig/Driver/
/usr/share/php/Horde/Mail/Autoconfig/Driver.php
/usr/share/php/Horde/Mail/Autoconfig/Driver/Guess.php
/usr/share/php/Horde/Mail/Autoconfig/Driver/Srv.php
/usr/share/php/Horde/Mail/Autoconfig/Driver/Thunderbird.php
/usr/share/php/Horde/Mail/Autoconfig/Exception.php
/usr/share/php/Horde/Mail/Autoconfig/Server/
/usr/share/php/Horde/Mail/Autoconfig/Server.php
/usr/share/php/Horde/Mail/Autoconfig/Server/Imap.php
/usr/share/php/Horde/Mail/Autoconfig/Server/Msa.php
/usr/share/php/Horde/Mail/Autoconfig/Server/Pop3.php