We have just discovered that the SharePoint Lists protocol is being deprecated by SmarterMail because it has been deprecated by Microsoft. We stumbled on this after discovering that most of our users who had configured AddToOutlook for Contact synchronization were having large numbers of conflicts, which we found in
"(all folders icon)... SharePoint Lists... Sync Issues". The interim workaround is to delete all conflicts or delete the sharepoint list and recreate it using AddToOutlook.
The Contact URL is only visible in the newer versions of SmarterMail. In the versions that have the patch, it is obtained in the same way as the Calendar URL, from the properties window.
We have not upgraded yet, but now I have incentive to do so soon. I am waiting for one more patch cycle to get the latest fixes for IMAP. Consequently, I have not tried CalCavSync with My Contacts, but I fully expect that it will work.