How Reliable Is Symantec’s sub-50% spam level?

Symantec’s June 2015 Intelligence Report includes some eye-catching numbers, and predictably generated a lot of quick press coverage. But how reliable is that figure? Unfortunately the publicly-available report is light on details and methodology, and doesn’t provide message volumes. Do other sources agree with their assessment?

“Email Authentication Basics” Slide Deck Now Available

A new presentation explaining the basics of how email authentication works is available from The concepts and common usage of SPF, DKIM, and DMARC are all covered in this introductory slide deck, which is made available under the Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA). You can download the 1.9MB PDF file clicking […]