Looks like the cpanel icon that used to show up for mail scanner config is missing in
WHM 11.15.0 cPanel 11.17.0-R19434
CENTOS Enterprise 4.6 i686 on standard - WHM X v3.1.0
mailscanner config icon
Are you running the latest version of the front-end? Have you tried reinstalling the front-end? If that doesn't work, try uninstalling the front-end (search the faq for uninstall) and then reinstalling it. We've got a VPS running the same versions of cPanel and the same OS and the icon is still there.