Romania and Panama, two of the world's notable sources of spam, now have fewer computers producing it, according to security vendor Cloudmark.
The U.S. remains first in having the most systems blocked by IP address for sending junk mail, though by the percentage of its total IP addresses, it ranks fairly low.
Cloudmark, which specializes in providing antispam products to ISPs, said it is blocking 13 percent fewer IP addresses worldwide for sending spam, with notable improvements in a few small countries, according to its first quarterly report for this year. The report covered IPv4 addresses, which are used for the vast majority of Internet traffic.
Cloudmark blocked between 20 percent and 25 percent of Romania's entire IP address space between November 2012 and April 2014 due to spam, but that's now down to 6.2 percent.
"While this is still high, it does represent significant progress in the past year," the report said.
Panama, which has a low number of IP addresses in relative terms, had more than 10 percent of its entire IP space blocked, Cloudmark said. That was mostly due to a hosting service called Panamaserver.com.
Now, only 1.5 percent of Panama's IP space is blocked. Spam coming from Panamaserver.com tends to be short runs of a few days rather than weeks, the report said.
Saudi Arabia, however, is being blocked more often. About 6.4 percent of its total IP space is blocked, due to ongoing issues with the largest ISP there, Saudinet.
"It appears to be the result of widespread botnet infections and compromised accounts rather than the situation in Romania and Panama, where the resources were purchased by spammers," Cloudmark said.
The top countries for the number of IP addresses blocked are the U.S., followed by China, Germany, Russia and then Romania, Cloudmark said.
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