Fall Out of Blocked Email Hits Thousands of Verizon Subscribers But Has Little Effect to Stem Spam

Verizon internet service division has recently changed policy which effectively blocks ordinary outgoing email from any non-Verizon address in a strategy aimed at reducing Verizon’s ignominious title as the largest ISPs in the United States permitting spam. Yet according to a published study by University of Texas Center for Research in Electronic Commerce, this step “did not stop increasing spam coming from Verizon…”.

Brian Krebs, a security expert blogger for Washington Post says, “Verizon.net is home to more than twice as many spam-spewing zombies as any other major Internet service provider in the United States, according to an analysis of the most recent data from anti-spam outfit Spamhaus.org.”

Recently Verizon spokesman Clifford Lee announced the company plans to shift to using Port 587 for e-mail originating on the Verizon network. This notice particularly affects Verizon DSL subscribers who have a professional email addresses associated with a business or organization using e-mail clients like Outlook, Outlook Express, Eudora and Thunderbird. Unless the e-mail is routed thorough Verizon e-mail server, email just sits in the Outbox.

In practical usage, some email clients and servers can be configured to use port 587 instead of 25, but there are numerous cases where this is not possible or convenient. Many third party providers do not recognize 587 as an allowable port. For instance, Networks Solutions has an alternative SMTP port 2525. However, Verizon does not recognize this access. Further testing shows, despite the ability to configure Port 587, it is impossible to log into a third party incoming mail server.

According to research Verizon Port 587 Requirement: Effects on Anti-Spam Blocklists published in July 2009 by University of Texas examined anti-spam blocking by Verizon over a three months period. The analysis of 31 Verizon owned ASNs (Autonomous System Numbers), concluded, despite the fact that Verizon has required the use of port 587, the tactic did not stop or even reduce spam coming from Verizon. In addition, study authors note that no other ISP has publicly announced port 587 requirements.

On August 8, 2001, Verizon made a similar move in New York which was quietly withdrawn when users objected to the address blocking by writing to the New York Public Utility Commission and the Federal Communication Commission.