One in four messages trashed, and it’s your fault
By Ken Magill
Magilla Marketing
August 28, 2007

Ken Magill writes a great article about the average delivery of email programs and a number of ISP Benchmarks, hot on the heals of this gem regarding the state of Direct Marketers and their mailing practices.

A few comments about this latest article:

the low delivery numbers are not a result of Internet service providers mistakenly trashing permission-based mail.

Blaming the Email Service Provider is also a a common reaction when delivery fails to reach the recipient, reading this article might bring to light some of the key drivers behind filtering and blocking. had the highest delivery rate with 97% of permission-based mail getting delivered

America Online uses the same filtering for,, Compuserve and Netscape users, yet these are filtering vastly different, when these should be almost identical. Something seems to be

Spamassassin has begun giving bad scores to e-mail with inaccurate Sender Policy Framework authentication records

This seems to be true if you have the Mail::SPF::Query extension installed, this is not yet part of the default Spamassassin 3.0 install.