If you want to set some preferences for the Sametime Connect client remotely you can do this via an update site. How to create such an update site and how to configure your Sametime server that these preferences will be forced to the clients as soon as they log in is described in these technotes:
Although both technotes are for Sametime 7.5.x the same procedure will work with the current 8.5.x clients.
In the first technote you will also find a sample update site where you just need to adapt the preference settings you want to deploy. You can find a list of the valid settings for the current 8.5.1 client in the infocenter.
There are two things I would like to mention as they are not obvious:
The sample for the setting "URL for UIM Proviosioning" in STCONFIG.NSF is a bad one. You will find "http:///STclientupdate/site.xml". This should better read "http://<full host name of your update site server>/STclientupdate/site.xml". So, do NOT forget to specifiy the full URL to your site.xml including the host name. Sametime will NOT add that automatically ...
And in the sample update site you will find the following line in the "feature.xml" within the "<required>" section:
<import feature="com.ibm.collaboration.realtime.application.feature" version="7.5.1" match="equivalent" />
This means, that the update will only be applied if you do have exactly the Sametime 7.5.1 installed. If you want to only apply that for another client version, e .g. 8.5.1 you need to change "7.5.1" to "8.5.1". If you want to apply the settings to all clients with version 7.5.1 or above you need to change the line to:
<import feature="com.ibm.collaboration.realtime.application.feature" version="7.5.1" match="greateOrEqual" />