I’ve setup an RBLDNS lookup at Docunext, here are some examples:

78.88.191.111

87.117.8.182

91.124.17.189

189.18.215.72

200.100.159.80

200.207.67.247

201.35.233.53

201.43.67.218

201.88.36.34

201.143.189.168

213.202.131.53

217.217.141.100

217.198.149.150

77.200.164.231

78.25.50.226

90.213.168.205

74.60.194.83

79.140.1.74

81.208.13.171

81.67.22.199

190.21.100.83

84.122.95.113

86.63.81.124

87.119.255.157

87.205.138.187

87.253.6.152

93.81.100.195

80.95.77.101

110.37.77.178

213.6.241.90

94.70.30.222

67.173.85.117

94.255.128.186

201.233.245.101

87.206.113.195

212.89.25.223

86.16.171.136

81.106.84.25

71.76.130.13

208.53.12.37

90.141.62.182

83.23.65.169

88.71.27.37

83.21.13.29

61.247.40.250

79.26.104.11

82.63.209.114

79.23.147.153

82.60.17.240

87.208.89.246

87.212.165.44

89.254.203.102

66.152.179.108

143.248.68.59

207.182.253.102

207.182.253.104

207.182.253.106

200.83.151.215

201.241.211.96

124.120.120.75

124.121.38.145

79.166.228.112

92.100.93.226

94.29.14.79

174.137.178.222

68.162.253.19

113.22.110.22

114.200.172.20

114.207.120.42

115.73.174.148

116.46.137.109

121.179.71.149

123.16.131.228

123.22.105.79

123.24.147.254

125.189.156.94

163.180.57.184

166.238.50.66

170.51.95.232

186.58.132.178

186.81.25.128

186.9.167.250

187.40.57.66

189.106.12.215

189.179.101.239

189.73.63.110

189.83.110.107

190.10.3.166

190.103.44.13

190.144.89.198

190.188.139.177

190.209.83.190

190.220.50.144

190.246.22.134

190.49.7.163

190.51.189.20

190.65.96.242

190.67.213.179

190.69.234.139

190.71.6.74

190.96.131.33

190.97.143.17

195.178.153.2

201.17.66.104

201.19.13.173

201.234.254.127

201.29.183.129

202.168.229.166

211.227.78.148

211.47.90.89

213.226.192.126

218.235.169.84

220.92.6.22

41.129.1.233

59.95.15.120

64.234.115.104

67.204.61.146

69.169.197.28

69.28.56.91

71.181.47.13

77.120.64.182

77.126.71.20

77.70.78.82

78.138.168.186

78.163.170.64

78.170.224.245

78.90.242.139

78.96.118.187

79.107.104.237

82.141.138.194

83.228.84.102

84.254.237.228

85.132.29.134

88.235.245.150

88.246.32.222

88.253.128.229

89.123.25.241

89.165.12.113

89.39.55.130

92.46.19.78

92.82.199.180

92.84.92.66

92.85.113.84

93.100.134.212

94.123.119.117

94.123.129.137

94.158.186.33

95.133.151.214

95.134.197.117

95.66.49.232

95.78.138.244

95.78.85.21