I have been reading though the code for cerberusweb.mail_filter.criteria and cerberusweb.mail_filter.action and they are create but I realized they are pre ticket creation (Pre-Parser Filter) it would be nice if you could add two more.
1) Mail-to-Group Routing aka Mail Routing inside the HelpDesk Setup.
2) Inbox Routing inside the group Setup.
This would allow even greater controls and would allow things like the following work. I am not sure if this will work with the upcoming cerberusweb.mail_filter.action but these two filters would make stuff like thing thread can be done.
New Feature
Open
[Filter] Additional Filter Criteria's and Action's to help round out the Extensions.