1. Step 1) Stop the SmarterMail site within IIS:
  2. Step 2) Uninstall SmarterMail
    1. The Domains directory(C:\SmarterMail\Domains\) and configuration files within your Program Files (x86)\SmarterTools\SmarterMail\Service\Settings directory should remain untouched during uninstall.
  3. Step 3) Install the latest SmarterMail build which can be downloaded from: https://www.smartertools.com/smartermail/downloads
  4. Step 4) Start the SmarterMail IIS Site - Verify everything is loading and working correctly.
Done.