Notify Administrators when email processing fails
In our implementation, occasionally the email processing rake task won't know what to do with an incoming email and it will simply skip the email, doing nothing with it. This is fine for the most part, but it requires someone to log into the email account periodically and make sure Redmine didn't drop an issue request or response to an issue's comment thread.
It would be extremely handy if Redmine would send a notification to administrators or even to a specific email address if the email processing rake task skipped an email that it didn't understand. This way, we'd know when it was necessary to intervene on mail processing manually.