Spam StatisticsPosted by Roger Keays, 4 November 2009, 3:51 PM |
Statistics from the spam filter deployed at Sunburnt Web Solutions:
| filter | blocked | blocked % | left | left % |
|---|---|---|---|---|
| Incoming Connections | 0 | - | 209,728 | 100% |
| Connection Limiting | 3,636 | 2% | 206,092 | 98% |
| Invalid HELO | 50,071 | 32% | 156,021 | 74% |
| Greylisting | 109,098 | 70% | 46,923 | 22% |
| RBL (IP Blacklisting) | 3,664 | 8% | 43,259 | 21% |
| URIBL (URL Blacklisting) | 234 | 1% | 43,025 | 20% |
| SPF | 0 | 0% | 43,025 | 20% |
| Heuristics | 383 | 1% | 42,642 | 20% |
| Bayesian | 3,085 | 7% | 39,557 | 19% |
| Total Spam / Legitimate | 170,171 | 81% | 39,557 | 19% |
This is a mature spam filter, and many spammers have stopping hitting the server since it was set up. At first, the stats were quite different. For example, connection limiting was hugely effective.
Invalid recipients aren't shown in these statistics because the number of recipients per connection or email is so variable. And of course, spammers do everything in bulk right? If you compared the total number of legitimate recipients to the total number of spam recipients it would be practically 0% legitimate.
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