Does anybody know how to configure this filter in Gmail?
I've tried various things like just having quotes, (no subject), subject:(no subject), etc.
I realized that doesn't work because when you look at the headers of an email with "no subject" in the subject line, the actual subject header line is completely missing.
I even exported a filter, edited the xml, then re-imported it taking out any characters from within the
value='' line. doesn't work either.