It is possible, but nontrivial, to set filters through the command line. Search the Administrators forum for "zmmailbox sieve". I don't think it's possible to "lock" filter rules.
Also try this. Save, don't sort!
Enter "has:attachment -is:sent" into the search box. That will very quickly find all messages with attachments not from yourself, regardless of the enclosing folder.
Click on the floppy disk icon to save the search as a virtual folder. Btw, I don't know that people under age 20 will necessarily recognize a floppy disk icon... |