Staff, crew leaders and right hand men are now able to mark mobmail as "Priority". This will cause them to be sorted to the top of the recipient's inbox. When viewing a priority mail there will be an exclamation mark icon, click that icon to make a mail no longer priority status. This also works with mass mail.

I (already) updated this. You no longer have to click to make a mail not priority. Simply viewing the mail will remove priority status.