Technical Guidance

Broken SPF…what does it mean?

People sometimes write in and ask "what is the impact of a broken SPF record"? The net effect of a broken SPF record is that receivers can't reliably use SPF to determine the legitimacy of the domain's email.  *Some* receivers might ignore the broken parts of an SPF record and keep checking, but out of…
dmarcian
10 October 2015
Technical Guidance

PTR mechanisms in SPF records

If PTR mechanisms are detected, the current diagnostic output is: Warning: PTR mechanisms SHOULD NOT be used and cannot be resolved using this diagnostic tool. What does the PTR mechanism mean?  When an email receiver gets a piece of email and the PTR mechanism is in the sender's SPF record, the receiver will look at…
dmarcian
9 October 2015

Brief history of email authentication

Email is huge (largest deployed application on the Internet?) and it takes a long time to change the fundamentals. 2003: First SPF draft 2004: First DomainKeys draft (predecessor to DKIM) 2006: First DKIM draft PayPal begins work with Yahoo on authentication-based model 2007: BITS Email Security Working Group publishes paper recommending TLS + SPF +…
dmarcian
5 October 2015