This module (authres) is designed to provide support for RFC 5451/7001,
originally http://tools.ietf.org/html/rfc5451 and currently
http://tools.ietf.org/html/rfc7001 processing in Python.

It also supports Authentication Results extensions:

RFC 5617 DKIM/ADSP
RFC 6008 DKIM signature identification (header.b)
RFC 6212 Vouch By Reference (VBR)
RFC 6577 Sender Policy Framework (SPF)
draft-kucherawy-dmarc-base DMARC
RFC 7281 Authentication-Results Registration for S/MIME
RFC 7293, The Require-Recipient-Valid-Since Header Field
and SMTP Service Extension, header field types

SPF authentication results can relate to either the HELO identity or the Mail
From. When creating header fields with SPF results, only set the identity
used to evaluate the SPF result that's reported. You can use multiple objects
to report both in a single header field. See the example in the tests file.

Homepage:
https://launchpad.net/authentication-results-python
