Some Things that Shorewall Does Not Do Tom Eastep 2003- 2005 Thomas M Eastep Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover, and with no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. This article applies to Shorewall 3.0 and later. If you are running a version of Shorewall earlier than Shorewall 3.0.0 then please see the documentation for that release
Shorewall Does not: Act as a Personal Firewall that allows internet access by application. If that's what you are looking for, try TuxGuardian. Work with an Operating System other than Linux (version >= 2.4.0) Act as a Proxy (although it can be used with a separate proxy such as Squid or Socks). Do content filtering: HTTP - better to use Squid and Dansguardian for that. Email -- Install something like Postfix on your firewall and integrate it with SpamAssassin , Amavisd-new and Clamav Configure/manage Network Devices (your Distribution includes tools for that).
In Addition: Shorewall generally does not contain any support for Netfilter Patch-O-Matic-ng features or any other features that require kernel patching -- Shorewall only supports features from released kernels except in unusual cases.