snowshoe spamming
adj.— «Like a snowshoe spreads the load of a traveler across a wide area of snow, some spammers use many frequently-changing IP addresses and domains to spread out the spam load in order to dilute recipient reputation metrics and evade filters. Conversely, legitimate mailers try hard to build their brand reputation based on a known domain and a small permanent range of sending IPs. Snowshoers also use anonymized or unidentifiable whois records, whereas legitimate senders are proud to provide their real identity.» —“Frequently Asked Questions (FAQ)” Spamhaus Sept. 15, 2008. (source: Double-Tongued Dictionary)