BrowseControl offers
the ability to restrict web page access
and application usage which could be used
to restrict the usage of web based email
and unauthorized email clients. You can
also use Browsecontrol's port blocker to
block email protocols such as POP3 and
SMTP. Through the combination of these
tools you are capable of restricting
virtually all forms of email usage. To
learn more about BrowseControl's
restriction capabilities from it
features page.