Cisco Cisco Email Security Appliance C160 Mode D'Emploi

IronPort AsyncOS supports several forms of email authentication to prevent email 
forgery. To verify incoming mail, AsyncOS supports Sender Policy Framework 
(SPF), Sender ID Framework (SIDF), and DomainKeys Identified Mail (DKIM). 
To sign outgoing mail, AsyncOS supports DomainKeys and DKIM.

With DomainKeys or DKIM email authentication, the sender signs the email 
using public key cryptography. The verified domain can then be used to detect 
forgeries by comparing it with the domain in the From: (or Sender:) header of the 
email. The current version of AsyncOS supports email signing for DomainKeys, 
and it supports both email signing and verification for DKIM. For more 
information about DomainKeys and DKIM, see 

SPF and SIDF email authentication allow the owners of Internet domains to use a 
special format of DNS TXT records to specify which machines are authorized to 
transmit email for their domains. Compliant mail receivers then use the published 
SPF records to test the authorization of the sending Mail Transfer Agent’s identity 
during a mail transaction. For more information about SPF and SIDF, see 

.

AsyncOS supports DomainKeys and DKIM authentication to prevent email 
forgery. DomainKeys and DKIM are mechanisms used to verify that the source of 
the email and the contents of the message were not altered during transit. DKIM 
is an enhanced protocol that combines DomainKeys specification with aspects of 
Identified Internet Mail to create an enhanced protocol called DomainKeys 
Identified Mail (DKIM). DomainKeys and DKIM consist of two main parts: 
signing and verification. The current version of AsyncOS supports the “signing” 
half of the process for DomainKeys, and it supports both signing and verification 
for DKIM. You can also enable bounce and delay messages to use DomainKeys 
and DKIM signing.

When you use DomainKeys or DKIM authentication, the sender signs the email 
using public key cryptography. The verified domain can then be used to detect 
forgeries by comparing it with the domain in the From: (or Sender:) header of the 
email.