GMS was written from the ground up to be a secure, stable and highly responsive messaging system. All security settings default to protecting your server immediately upon installation, unlike many other messaging servers which are open to abuse by default.
The range of security features available is impressive providing complete protection for your system and includes
- Protection from relay abuse. Relay is restricted to a specified range of IP addresses, during installation this is set to a Class C IP address range based on the primary IP address attached to your network adapter.
- Check all inbound and outbound mail for viruses. Includes a fast multi threaded anti-virus engine. Virus signature files are constantly updated using, Gordano’s patent pending, firewall friendly update mechanism.
- Check all inbound and outbound mail for unwanted content. All messages can be checked for unwanted content, including Base64 encoded messages.
- Specify a range of attachment types that are not acceptable.
- The number of simultaneous connections to the server from a remote IP address can be limited. Prevents a well known Denial of Service attack to simply fill your server connections so that no genuine connections can be accepted.
- The number of bad commands accepted by a service can be limited, and the connection dropped when this limit is reached. This can also be used to tie up your connections, in a similar way to above and could be seen as another type of Denial of Service attack.
- Inactivity timeouts can be set for each of the protocols supported by GMS. Once again preventing all your connections being tied up unnecessarily.
- Access to the server can be restricted to known ranges of IP addresses
- A comprehensive password policy can be automatically maintained
- Verify the authenticity of senders through a range of DNS lookups
- Ban unwanted hosts from connecting to your server at all
- A range of Artificial intelligence features are supplied that monitor your server for any unusual activity, and shut off the server to any that is found. This is not only a good defence against Denial of Service attacks, it also monitors the sender and recipients of each message and its use has been found to considerably reduce the amount of spam flowing through a mail server.
In addition to the above, there are also a number of options to enforce or check for compliance with Internet Messaging standards. These not only help to protect your system but will also force non compliant messages into compliance. For example if a From or To header is missing from a message GMS will automatically insert one for you. These compliance checks can also be used to protect your internal mail clients such as Outlook which can have issues displaying non standard messages.