What percent of email is spam you ask? Since I work at a datacenter and ISP, we have a spam filter solution for tens of thousands of email accounts that filters 12 to 20 million emails per day. I came across this chart the other day that will give you a visual idea of what percent of email is spam. As of early 2009, 99.5% of all email passing through our spam filter is not delivered, or is flagged as spam. This is unbelievable! I can’t believe email actually works!
Unfortunately a lot of the time email doesn’t work. I run an online business and regularly our important message about a customer’s order is not delivered. We have two email accounts in use for the business, one of them a gmail account and both send in plain text. Important messages are sent to the customer twice, once through each account and very often neither message reached the customer’s inbox. Today the spam filters are doing an amazing job, but I feel there is a high probability that within a few years email will be on it’s way out because it’s not reliable and the spammers will reign.