For improving security and performance, Gibraltar includes several powerful proxy servers. Proxy servers are used for the following areas in Gibraltar:

E-mail proxy (SMTP, POP3)

Gibraltar acts as a secure mail relay. Depending on the type of e-mail traffic, a SMTP or POP3 proxy server can be activated between the Internet and an internal mail server (e.g. Exchange Server). Thus, the internal mail server is neither accessible, nor vulnerable from the Internet. Gibraltar acts as a proxy and receives all incoming mails, checks them against viruses and spam, and finally redirects them to the internal mail server.

Web proxy (HTTPS, HTTP)

The Gibraltar web proxy can be used both to improve security and as a caching proxy, to improve the performance of the web. The Gibraltar web proxy is able to check all downloads and websites for viruses and other potentially dangerous contents. Furthermore there is the possibility to restrict the access to the Internet for all users using Active Directory, LDAP or simply Access Control Lists (ACL).

The http proxy can optionally be operated transparent. This means, that explicit client configuration is not necessary. The Firewall simply redirects all regular web requests to the local web proxy.

FTP proxy (FTP)

Gibraltar is able to check both incoming and outgoing FTP data transfers against viruses. Additionally, the FTP proxy protects the internal FTP server against attacks.