It should, although it should also be noted that development for WebSitePanel ended in August 2015 and has since been forked to MSPControl and SolidCP.

 

We migrated our WebSitePanel installation a couple months back to MSPControl about the same time we finally got around to upgrading from v14 to v15 of SmarterMail and the newer version of SmarterMail does work fine with MSPControl. It should work still with WebSitePanel, in theory, but I can't say for certain.