Houtan,

The Brute-Force IDS rules for webmail are managed by IIS which is why you can't find them in the SmarterMail IDS Rules. You can find those settings contained in your \SmarterMail\MRS\web.config. There should be the following lines:

    <add key="ForgotPassword.BruteForceDetection.TriesBeforeBlock" value="10" />
    <add key="ForgotPassword.BruteForceDetection.BlockTime" value="5" />
    <add key="Login.BruteForceDetection.TriesBeforeBlock" value="10" />
    <add key="Login.BruteForceDetection.BlockTime" value="5" />

You can modify the values as desired (they are in minutes).

Post-Script: If you change these values from their defaults you may have to do so every time you install a SmarterMail update as the \SmarterMail\MRS\web.config gets overwritten during the update process regardless of whether you use the .EXE or .MSI method.