Spam Filter ECE 404 Homework #11 Due: Thursday 4/14/2022 at 5:59PM Design spam filter recipes that will trap all 74 messages that you will find in the gzipped tar archive junkMail.tar.gz uploaded on Brightspace along with the assignment. When you gunzip and untar the archive with, say, tar -zxvf junkMail.tar.gz you’ll see 74 individual spam messages with names junkMail 1 through junkMail 74. About these messages: 1. junkMail 1 through junkMail 50 : The headers of all these messages have one thing in common: they contain multiple entries in the “From:” header. All these messages were trapped by a single recipe in your instructor’s spam filter. The regex in your instructor’s recipe has only 40 characters in it. (If the regex engine used by procmail allowed for Perl’s ′{}′ metacharacters, this regex could have been made as short as just 10 characters.) 2. junkMail 51 through junkMail 63 : These messages can be trapped just on the basis of the “Subject:” line in the email headers. 3. junkMail 64 through junkMail 66 : In your instructor’s spam filter, these messages were trapped on basis of the content (email body) of the messages. 4. junkMail 67 through junkMail 74 : You need to trap these with a single recipe that contains compound rules. Below is an example of a recipe with compound rules. It is NOT the compound recipe for trapping the messages junkMail 67 through junkMail 74: :0 H