Today I had to work on the Plesk server webmail vacation responder settings, and looking at the Horde webmail option I found that this is not available in the default Horde Install in Plesk 9. Digging through many google search pages and search phrases I found a very useful and working link given below.
Small change in the above guide is that on the Debian System you can install vacation application directly using the “apt-get”. Just execute the following command:
apt-get install vacation
After configuration when you open the vacation page on the webmail then most probably you were greeted by a warning message that the Plesk driver on Horde Vacation responder requires Horde_DOM installed. The repository address given in the warning message is no more working. It took me around an hour to find this file “DOM.php”, on some blog.
Unzip the archive and put this file DOM.php at location – /usr/share/psa-horde/lib/Horde/ .
If everything works well then now you can set the Vacation responder from the Webmail interface of the Horde Webmail.