[horde] Auto responder plugin

[Leo Prince]

Hello All,

I am in search of an auto responder plugin for Horde. I have Horde with 
5.1.5 and want to make use of auto responders while I am out of the office.

The "Vacation" plugin tried and found not working. Installed the 
Vacation correctly. See screenshot

http://awesomescreenshot.com/0f32rlsbc8

But when trying to access it, It is encountering with the following PHP 
error.

=========

Fatal error: Using $this when not in object context in 
/usr/share/psa-horde/config/registry.php on line 73

=========

Seems like Horde and Vacation is using the same registry.php and 
Vacation doesn't like the PHP code the way Horde uses. So any help to 
resolve this ?

Is this something related with a bad release of Vacation. Does the older 
version of Vacation will work ? Please advise.

I see there is no stable release for vacation in your modules page.

http://www.horde.org/development/modules

However is there any other substitute that I can use in for Vacation ? 
If there any please let me know so that I can try that.

In the meantime, What is Sork. I see this from the following link. 
Please see

http://www.horde.org/apps/sork

Is there any possibility to use this for auto responder purposes ?

Thank in advance for looking into this.

Thanks and Regards,
Leo.