Less than five percent of all email is delivered to mailboxes, as the rest is junk blocked by spam-fighting efforts, according to Enisa, the European Network and Information Security Agency.
The agency reported the finding in a report, published on Thursday, on anti-spam measures taken by European ISPs in 2009. While these measures are well used by providers, junk email remains a key problem for them and takes up a large part of their annual budgets, according to the report.
ISPs surveyed by the agency said nearly 80 percent of all SMTP connections were aborted, mainly because a match had occurred against a blacklist. Of the connections that were accepted, almost 80 percent were filtered out, mostly as spam, it added in its report released on Thursday.
The result is that only 4.4 percent of all email was delivered, down from six percent in Enisa’s last spam report two years ago, the agency said.