Site being spidered by spammers

I moved some message archives (111,000) messages to harptab.com and I just noticed that the site is getting 40,000 hits a day for the last few days. The ip address in the logs indicates that it is the African Network Information Center who is accessing my site. I guess that they are skimming off emails. I will change the code to obsfucate the addresses, but the damage is done. I hate spammers!