Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

Relaxed. The “relaxed” header canonicalization algorithm performs the 
following: empty lines are stripped at the end of the body, white spaces are 
reduced to a single space within lines, and trailing white spaces are stripped 
in lines. 

Simple. Empty lines at the end of the body are stripped.

Select a signing key (If you have already created a signing key, otherwise, skip to 
the next step). You must create (or import) at least one signing key in order to have 
signing keys to choose from in the list. See 

Select the list of headers to sign. You can select from the following headers:

All. AsyncOS signs all the headers present at the time of signature. You may 
want to sign all headers if you do not expect headers to be added or removed 
in transit.

Standard. You may want to select the standard headers if you expect that 
headers may be added or removed in transit. AsyncOS signs only the 
following standard headers (if the header is not present in the message, the 
DKIM signature indicates a null value for the header):

From

Sender, Reply To-

Subject

Date, Message-ID

To, Cc

MIME-Version

Content-Type, Content-Transfer-Encoding, Content-ID, 
Content-Description

Resent-Date, Resent-From, Resent-Sender, Resent-To, Resent-cc, 
Resent-Message-ID

In-Reply-To, References

List-Id, List-Help, List-Unsubscribe, LIst-Subscribe, List-Post, 
List-Owner, List-Archive

When you select “Standard”, you can add additional headers to sign.