We are using ZCS release 7.2.0 on a CentOS 5.9 machine.

(1) Does this version of Zimbra have the capability to create a whitelist that would only be used by one of our users (and therefore would not affect anyone else)?

(2) And if so, could someone please give me a link to the instructions on how to do this?

I did see one posting on the Zimbra forum that had the following idea:
<Begin User's Idea>
One way to do this might be to setup a filter. Have the filter read something like:

Select the option "All Conditions"
* size over 1
* From does not contain friendly_user@somedomain.com
* From does not contain dad@this_domain.com
* From does not contain mom@some_otherdomain.com

And then for "Perform the following actions", you can choose "Discard".
<End User's Idea>

The main issue with this is that I have found that the filter rules do not always seem to be followed.

Any help would be appreciated.