as51430.net spammed me, so here is the research for tracking and banning. as51430.net is out of Luxembourg. I did not get spammed by its three sister host names, lux-net-ip.as51430.net, nld-net-ip.as51430.net, and swe-net-ip.as51430.net.
Observation:
lu-customer-ip.as51430.net found the following IPs:
91.214.44.48
91.214.45.104
91.214.46.167
79.142.78.169
Research:
Further research found the following host names that change often: lux-net-ip.as51430.net, nld-net-ip.as51430.net, and swe-net-ip.as51430.net. Maybe they stand for Luxembourg, Netherlands, Sweden? Here is the complete list by ip address, so you can ban all three.
swe-net-ip.as51430.net 31.3.152.106
swe-net-ip.as51430.net 31.3.154.102
swe-net-ip.as51430.net 31.3.159.84
lux-net-ip.as51430.net 37.46.113.23
lux-net-ip.as51430.net 37.46.113.35
lux-net-ip.as51430.net 37.46.113.103
nld-net-ip.as51430.net 37.46.118.117
nld-net-ip.as51430.net 37.46.118.218
nld-net-ip.as51430.net 37.46.118.245
swe-net-ip.as51430.net 37.46.121.235
swe-net-ip.as51430.net 37.46.121.240
swe-net-ip.as51430.net 37.46.122.3
swe-net-ip.as51430.net 37.46.122.197
nld-net-ip.as51430.net 37.46.127.165
nld-net-ip.as51430.net 79.142.64.240
nld-net-ip.as51430.net 79.142.66.222
nld-net-ip.as51430.net 79.142.67.24
nld-net-ip.as51430.net 79.142.67.28
nld-net-ip.as51430.net 79.142.67.140
nld-net-ip.as51430.net 79.142.67.214
nld-net-ip.as51430.net 79.142.71.63
nld-net-ip.as51430.net 79.142.73.67
nld-net-ip.as51430.net 79.142.73.106
nld-net-ip.as51430.net 79.142.74.124
nld-net-ip.as51430.net 79.142.75.224
nld-net-ip.as51430.net 79.142.75.225
swe-net-ip.as51430.net 79.142.76.216
swe-net-ip.as51430.net 79.142.77.174
nld-net-ip.as51430.net 104.20.37.55
swe-net-ip.as51430.net 104.20.37.55
nld-net-ip.as51430.net 104.20.38.55
swe-net-ip.as51430.net 128.127.104.135
swe-net-ip.as51430.net 128.127.104.200
nld-net-ip.as51430.net 128.127.106.234
nld-net-ip.as51430.net 128.127.106.243
nld-net-ip.as51430.net 128.127.111.17
nld-net-ip.as51430.net 185.2.29.13
nld-net-ip.as51430.net 185.2.29.191
nld-net-ip.as51430.net 185.2.29.202
nld-net-ip.as51430.net 185.2.31.95
nld-net-ip.as51430.net 185.2.31.117
nld-net-ip.as51430.net 185.10.57.21
nld-net-ip.as51430.net 213.5.65.170
nld-net-ip.as51430.net 213.5.66.1
nld-net-ip.as51430.net 213.5.68.13
nld-net-ip.as51430.net 213.5.66.14
nld-net-ip.as51430.net 213.5.69.135
nld-net-ip.as51430.net 213.5.70.90
nld-net-ip.as51430.net 213.5.70.193
nld-net-ip.as51430.net 213.5.71.1
nld-net-ip.as51430.net 213.5.71.61
nld-net-ip.as51430.net 213.5.71.102
Here is the list by host name, just in case you get hit by only one:
lux-net-ip.as51430.net 37.46.113.103
lux-net-ip.as51430.net 37.46.113.23
lux-net-ip.as51430.net 37.46.113.35
nld-net-ip.as51430.net 37.46.118.117
nld-net-ip.as51430.net 37.46.118.218
nld-net-ip.as51430.net 37.46.118.245
nld-net-ip.as51430.net 37.46.127.165
nld-net-ip.as51430.net 79.142.64.240
nld-net-ip.as51430.net 79.142.66.222
nld-net-ip.as51430.net 79.142.67.140
nld-net-ip.as51430.net 79.142.67.214
nld-net-ip.as51430.net 79.142.67.24
nld-net-ip.as51430.net 79.142.67.28
nld-net-ip.as51430.net 79.142.71.63
nld-net-ip.as51430.net 79.142.73.106
nld-net-ip.as51430.net 79.142.73.67
nld-net-ip.as51430.net 79.142.74.124
nld-net-ip.as51430.net 79.142.75.224
nld-net-ip.as51430.net 79.142.75.225
nld-net-ip.as51430.net 104.20.37.55
nld-net-ip.as51430.net 104.20.38.55
nld-net-ip.as51430.net 128.127.106.234
nld-net-ip.as51430.net 128.127.106.243
nld-net-ip.as51430.net 128.127.111.17
nld-net-ip.as51430.net 185.10.57.21
nld-net-ip.as51430.net 185.2.29.13
nld-net-ip.as51430.net 185.2.29.191
nld-net-ip.as51430.net 185.2.29.202
nld-net-ip.as51430.net 185.2.31.117
nld-net-ip.as51430.net 185.2.31.95
nld-net-ip.as51430.net 213.5.65.170
nld-net-ip.as51430.net 213.5.66.1
nld-net-ip.as51430.net 213.5.66.14
nld-net-ip.as51430.net 213.5.68.13
nld-net-ip.as51430.net 213.5.69.135
nld-net-ip.as51430.net 213.5.70.193
nld-net-ip.as51430.net 213.5.70.90
nld-net-ip.as51430.net 213.5.71.1
nld-net-ip.as51430.net 213.5.71.102
nld-net-ip.as51430.net 213.5.71.61
swe-net-ip.as51430.net 31.3.152.106
swe-net-ip.as51430.net 31.3.154.102
swe-net-ip.as51430.net 31.3.159.84
swe-net-ip.as51430.net 37.46.121.235
swe-net-ip.as51430.net 37.46.121.240
swe-net-ip.as51430.net 37.46.122.197
swe-net-ip.as51430.net 37.46.122.3
swe-net-ip.as51430.net 79.142.76.216
swe-net-ip.as51430.net 79.142.77.174
swe-net-ip.as51430.net 104.20.37.55
swe-net-ip.as51430.net 128.127.104.135
swe-net-ip.as51430.net 128.127.104.200