Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

When you configure domain profiles and signing keys in a clustered environment, 
note that the Domain Key Profile settings and Signing Key settings are linked. 
Therefore, if you copy, move or delete a signing key, the same action is taken on 
the related profile. 

A signing key is the private key stored on the Cisco IronPort appliance. When 
creating a signing key, you specify a key size. Larger key sizes are more secure; 
however, larger keys also can impact performance. IronPort supports keys from 
512 bits up to 2048 bits. The 768 - 1024 bit key sizes are considered secure and 
used by most senders today. Keys based on larger key sizes can impact 
performance and are not supported above 2048 bits. For more information about 
creating signing keys, see 

If you are entering an existing key, simply paste it into the form. Another way to 
use existing signing keys is to import the key as a text file. For more information 
about adding existing signing keys, see 

Once a key is entered, it is available for use in domain profiles, and will appear in 
the Signing Key list in the domain profile: