I'm trying to figure out how I can write a filter for Gmail that will match on the number of email addresses in the "To" field (plan to do the same for the "Cc" field as well, so if it counts both, that's a bonus.
What I want to do is match messages that have over say, 10 people in the To and/or CC fields, in order to catch mass forwards where the sender didn't bother to use Bcc. I can't seem to figure out a way to do this with the filtering options that are there. Am I overlooking something or is there really no way to do this?