SPF

[whalghamdi]

Hi CISCO Community 

I can not understand what is means in email header : SPF: helo identity postmaster@[127.0.1.1] None

Please explain! 

[balaji.bandi]

In email SPF most initial part of the conversation for Authenticating the envelope.

postmaster@[127.0.1.1]  - Most cases this is internal with a server loopback address.

RFC explains better  what None means :

https://tools.ietf.org/id/draft-ietf-spfbis-4408bis-09.html#rfc.section.11.2