Mail: The Anonymous Group

The Anonymous group is used in any situation where a suitable group for the sender or recipient cannot be found.

For the sender:

• If the sender's address is from the Opendium server's primary or secondary domains and the user exists on the system, the user's groups are used.
• If the sender's IP address is contained in any of the networks set up in Users & Groups, the appropriate networks' groups are used.
• For everything else, the sender is deemed to be in the Anonymous group.

For the recipient:

• If the recipient's address is to the Opendium server's primary or secondary domains and the user exists on the system, the user's groups are used.
• If the recipient's address is to the Opendium server's primary or secondary domains and the user does not exist on the system, the recipient is deemed to be in the Anonymous group.

The Anonymous group is extremely useful if you have a separate local mail server within your network. If the Anonymous group is set to redirect mail to your mail server, emails to any recipient that does not exist on the Opendium system will be forwarded on to your mail server. This can be put to good use where some of your users use the Opendium server for their email and some use a different server. Additionally, if all of your users retrieve their email from a separate mail server, setting a redirect on the Everyone group will be inherited by the entire groups hierarchy, causing all mails to be redirected, whether or not the recipient exists on the Opendium system.

Note: Do not allow the Anonymous group to perform unauthenticated mail relaying to external domains, as this will cause the system to act as an open mail relay!