Cost of Spam and Why Use Anti-Spam Filter (07 Nov 2006) E-mail is now being abused. The flow of spam on the Internet is the proof. It is annoying to download hundreds of disgusting spam emails into the inbox looking for some legitimate messages. Not only you waste your valuable time to delete junk emails by hand, you also waste your money as each spam message in your inbox takes precious kilobytes of bandwidth you paid for.