We use a Barracuda Email Archiver with a trusted App and Retention. Only One account that I am aware of will Not let the user delete the trash. If I remove the Retention the user can delete all the trash. (They had about 1 Month of Trash and 8200 messsages.)
If I add the retention back it Locks his ability to delete trash. The Archiver has the message recorded, so I am assuming it has set the flag to allow deleting.
Where should I look since only one account seems to show this symptom?