Spam clogs up bandwidth and storage for enterprises as well as ISPs. Spam reduces employee productivity as users forced to sift through dozens of unwanted messages. AOL, Yahoo! and Microsoft have announced a partnership to develop guidelines for fighting spam. 30 or more states have passed antispam laws of one kind or another. Some products use a bewildering array of techniques to block e-mail coming from servers used by spammers. Other techniques include lexical analysis, which scans certain words in certain words to block spam.”]
Source: https://www.csoonline.com/article/2116103/beating-back-the-onslaught-of-spam.html