Here are some stats from my spam blacklists over the past few months. This is based on around 80,500 blocked messages. Sampling I’ve done indicates that over 99% of these messages are truly spam. In fact, I’m only aware of one case of a false positive with this system.

Remember, this isn’t really related to where the spam I do receive comes from. This only counts messages that were blocked by my Sendmail blacklists before they got to my spam filters.

Top 10 blocked hostnames:
hanmail.net: 660 messages (0.820% of total blocked)
globalnetworks.co.kr: 472 messages (0.586% of total blocked)
yahoo.co.kr: 118 messages (0.147% of total blocked)
webmail.castwise.com: 97 messages (0.120% of total blocked)
203-236-237-100.rev.nextel.co.kr: 50 messages (0.062% of total blocked)
englishsoft.co.kr: 43 messages (0.053% of total blocked)
203-236-242-180.rev.nextel.co.kr: 38 messages (0.047% of total blocked)
optin-magic.com: 35 messages (0.043% of total blocked)
realwow.co.kr: 30 messages (0.037% of total blocked)
foomedia.com: 26 messages (0.032% of total blocked)

Top 10 blocked IP addresses:
203.246.56.130: 726 messages (0.902% of total blocked)
211.58.237.177: 629 messages (0.781% of total blocked)
211.204.75.214: 582 messages (0.723% of total blocked)
211.245.93.15: 521 messages (0.647% of total blocked)
61.32.61.240: 510 messages (0.634% of total blocked)
211.212.93.71: 492 messages (0.611% of total blocked)
211.227.184.222: 490 messages (0.609% of total blocked)
218.146.244.26: 478 messages (0.594% of total blocked)
211.232.128.66: 445 messages (0.553% of total blocked)
211.49.148.203: 435 messages (0.540% of total blocked)

Top 10 /24 networks blocked:
218.233.133: 758 messages (0.942% of total blocked)
203.246.56: 726 messages (0.902% of total blocked)
211.227.184: 676 messages (0.840% of total blocked)
211.58.237: 629 messages (0.781% of total blocked)
211.189.119: 584 messages (0.725% of total blocked)
211.204.75: 582 messages (0.723% of total blocked)
211.33.103: 569 messages (0.707% of total blocked)
218.146.244: 539 messages (0.670% of total blocked)
211.232.128: 522 messages (0.648% of total blocked)
211.245.93: 521 messages (0.647% of total blocked)

Top 10 /16 networks blocked:
61.73: 2284 messages (2.837% of total blocked)
211.109: 1892 messages (2.350% of total blocked)
211.58: 1679 messages (2.086% of total blocked)
218.48: 1579 messages (1.961% of total blocked)
211.204: 1493 messages (1.855% of total blocked)
211.219: 1347 messages (1.673% of total blocked)
211.212: 1280 messages (1.590% of total blocked)
211.245: 1194 messages (1.483% of total blocked)
211.243: 1153 messages (1.432% of total blocked)
218.233: 1135 messages (1.410% of total blocked)

Top 10 /8 networks blocked:
211: 44752 messages (55.592% of total blocked)
61: 14481 messages (17.989% of total blocked)
218: 11673 messages (14.500% of total blocked)
210: 6108 messages (7.587% of total blocked)
203: 1072 messages (1.332% of total blocked)
200: 216 messages (0.268% of total blocked)
202: 186 messages (0.231% of total blocked)
217: 7 messages (0.009% of total blocked)
164: 6 messages (0.007% of total blocked)
66: 5 messages (0.006% of total blocked)