Interrupt if you got your names confused, and you were talking about horde;
if you are using SME 8b6, you should have Horde V3
My SME 8b6 reports: Horde 3.3.11
If for some reason you have older version than that, try this:
yum --enablerepo=smecontribs update
But if you were talking about wordpress in this thread, like Charlie said:
.... it is considered impolite to hijack a thread. Wordpress is not horde.
As far as Horde V4, it looks nice on their web page, but I had so many problems with previous version (destroying html emails and destroying email when forwarding them) I started to use SME contrib Group Office, it handles emails much better.
But if Horde4 has fixed their previous issues, I might give it a try again.
Interested to try it out once Horde4 makes it into SME 8.