Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

When you configure AsyncOS for SPF/SIDF verification, it places an SPF/SIDF 
verification header (

Received-SPF

) in the email. The 

Received-SPF

 header 

contains the following information:

verification result - the SPF verification result (see 

).

identity - the identity that SPF verification checked: HELO, MAIL FROM, 
or PRA.

receiver - the verifying host name (which performs the check).

client IP address - the IP address of the SMTP client.

ENVELOPE FROM - the envelope sender mailbox. (Note that this may be 
different from the MAIL FROM identity, as the MAIL FROM identity cannot 
be empty.)

x-sender - the value of the HELO, MAIL FROM, or PRA identity.

x-conformance - the level of conformance (see 

) and whether a downgrade of the PRA check was 

performed. 

The following example shows a header added for a message that passed the 
SPF/SIDF check:

The 

spf-status

 and 

spf-passed

 filter rules use the received-SPF header to 

determine the status of the SPF/SIDF verification. 

Received-SPF: Pass identity=pra; receiver=box.example.com;

    client-ip=1.2.3.4; envelope-from="alice@fooo.com";

    x-sender="alice@company.com"; x-conformance=sidf_compatible