Summary: A filter that allows you to filter out any messages not sent to a particular realm message group.
Details: It can often be an annoyance to have to sift through endless messages to find the ones sent to a message group you belong to. Particularly when the discussions there are vitally important, having to dredge through dozens of other messages can be a drag. Adding a filter to only display letters sent to a particular group would be a most welcome addition, allowing you to get only the letters you need, neatly compiled together.
Benefits: See above
Possible exploits: None come to mind.
