I kept receiving a few errors when trying to reinstall Horde Webmail edition, one of them which was:

Failed opening required '/var/www/horde/lib/Applica tion.php' (include_path='.:/usr/share/php:/usr/share/pear') in /usr/bin/webmail- install on line 17

Obviously something didn't uninstall completely. I was unable to reinstall Horde Groupware Webmail Edition until I typed the following command which completely uninstalls all Horde PEAR packages, allowing a fresh brand new install of Horde to complete without errors..

pear uninstall `pear list -c horde | tail -n +4 | awk '{ print "horde/"$1 }'`

Yeah, just running that line which took a while to complete completely uninstalled every PEAR package related to Horde. After that, I was able to install horde from PEAR without any problems using the instructions found here.

Oh, and if you want to know where I found the above mentioned fix, you can find it on the Horde wiki, with some variations.

I need to get up to speed with PEAR. It sure does seem like an interesting way to install software.