When on Plesk, Horde becomes PSA-HORDE that has one real major difference that the original HORDE does not, it has advertising to it’s left

If there is one thing that differentiates Paid mail hosting from Free hosting (Since google allows you to host your mail domain), it is the No-Advertising feature, and plesk took that away.

Anyway, i am not taking any of this advertising thing, i know horde and i know they can not possibly hide it from me, After all the PHP code of horde is there.

The file that needs edeting is

/usr/share/psa-horde/templates/portal/sidebar.inc

Find the line that reads
if (window.NewsFeeds) {
and make it

if (false) {

Even when you do this, when Plesk updates Horde again, it will probably overwrite this, But modifeying this at every update is the easiest sollution i can think of besides dissabeling Plesk updates (Which is very dangerous)