Cisco Cisco Email Security Appliance C190 Guia Do Utilizador
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Cisco AsyncOS 8.5.5 for Email Security User Guide
Chapter 18 Cisco Email Encryption
Encrypting Messages using the Email Security Appliance
•
High Security. The recipient must always enter a password to open encrypted messages.
•
Medium Security. The recipient does not need to enter credentials to open the encrypted message
if the recipient credentials are cached.
if the recipient credentials are cached.
•
No Password Required. This is the lowest level of encrypted message security. The recipient does
not need to enter a password to open the encrypted message. You can still enable the read receipts,
Secure Reply All, and Secure Message Forwarding features for envelopes that are not
password-protected.
not need to enter a password to open the encrypted message. You can still enable the read receipts,
Secure Reply All, and Secure Message Forwarding features for envelopes that are not
password-protected.
Step 9
To enable users to open your organization’s URL by clicking its logo, you can add a link to the logo.
Choose from the following options:
Choose from the following options:
•
No link. A live link is not added to the message envelope.
•
Custom link URL. Enter the URL to add a live link to the message envelope.
Step 10
(Optional) Enable read receipts. If you enable this option, the sender receives a receipt when recipients
open the secure envelope.
open the secure envelope.
Step 11
(Optional) Click Advanced under Envelope Settings to configure the following settings:
•
Enter the length of time (in seconds) that a message can be in the encryption queue before timing
out. Once a message times out, the appliance bounces the message and sends a notification to the
sender.
out. Once a message times out, the appliance bounces the message and sends a notification to the
sender.
•
Select an encryption algorithm:
–
ARC4. ARC4 is the most common choice, providing strong encryption with minimal
decryption delays for message recipients.
decryption delays for message recipients.
–
AES. AES provides stronger encryption but also takes longer to decrypt, introducing delays for
recipients. AES is typically used in government and banking applications.
recipients. AES is typically used in government and banking applications.
•
Enable or disable the decryption applet. Enabling this option causes the message attachment to be
opened in the browser environment. Disabling this option causes message attachments to be
decrypted at the key server. If you disable this option, messages may take longer to open, but are not
dependent on the browser environment.
opened in the browser environment. Disabling this option causes message attachments to be
decrypted at the key server. If you disable this option, messages may take longer to open, but are not
dependent on the browser environment.
Step 12
In the Message Settings section, do the following:
•
To enable secure reply all feature, check the Enable Secure Reply All check box.
•
To enable secure message forwarding feature, check the Enable Secure Message Forwarding
check box.
check box.
Step 13
(Optional) If you have selected Cisco Registered Envelope Service and this service supports localization
of envelopes, enable localization of envelopes. In Notifcation Settings section, check the Use Localized
Envelope check box.
of envelopes, enable localization of envelopes. In Notifcation Settings section, check the Use Localized
Envelope check box.
Note
If you enable localization of envelopes, you cannot select encrypted message HTML or text
notification.
notification.
If you want to set the default locale of the envelope, see
.
Step 14
Select the HTML and text notification templates.
Note
The key server uses an HTML or text notification based on the recipient’s email application. You
must configure notifications for both.
must configure notifications for both.