If 99% of all email is spam, and your ISP blocks 99% of all spam, what
percentage of your email should be spam?
Without thinking, the answer may seem to be 1%, but it’s actually
closer to 50%.
- For every 10000 emails you receive, 9900 are spam and 100 are
legitimate (99% of email is spam).
- Your ISP blocks 99% of the 9900 spams, letting only 1% of the
spams into your mailbox.
- One percent of 9900 spams is 99 spams.
- So, you receive 100 legitimate messages and almost as many spam
messages, even though your ISP is filtering 99% of all spam!
- Many people incorrectly think that, if 50% of their email is spam,
their ISP is only blocking 50% of spam. Not true!