Quick recap from my notes (assuming you are on SME 9 and using RoundCube for webmail is an option for you - no idea if/how it works with horde/ingo):
1. install smeserver-dovecot-extras according to
http://wiki.contribs.org/Dovecot-extras2. install smeserver-roundcube according to
http://wiki.contribs.org/RoundCube#For_SME9
EDIT 2014-11-29: new version of smeserver-roundcube (1.1-4) released today already includes managesieve, so the following steps are no longer necessary (see also
http://bugs.contribs.org/show_bug.cgi?id=8697#c15 ). Simply do a
yum --enablerepo=stephdl upgrade smeserver-roundcube
and you should be set.
3. add "managesieve" to the list of roundcube plugins in SME configuration database, eg.:
- first check which plugins are already enabled by default:
config getprop roundcube PluginsList
- then add managesieve plugin to the list if it is not already in there:
config setprop roundcube PluginsList `config getprop roundcube PluginsList`,managesieve
4. Until it is eventually integrated in the roundcube contrib, get the latest version of the custom template script for the managesieve-plugin configuration which is attached to
http://bugs.contribs.org/show_bug.cgi?id=8697 , and place it in the corresponding folder:
tar xvfz config.inc.php.tar.gz
mkdir -p /etc/e-smith/templates-custom/opt/roundcube/plugins/managesieve
mv config.inc.php/ /etc/e-smith/templates-custom/opt/roundcube/plugins/managesieve/
expand-template /opt/roundcube/plugins/managesieve/config.inc.php
5. In the roundcube settings for every user, there should now be a new item "Filter". If you need a seperate roundcube settings panel for vacation messages, there's also an option near the bottom of the config.inc.php file that can be changed accordingly

PS.: Be aware of
http://bugs.contribs.org/show_bug.cgi?id=8694 if you have smeserver-mailsorting installed; this may break sieve functionaity as well.