Cisco Cisco Email Security Appliance C680 User Guide

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Chapter 12      IronPort Email Encryption
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Cisco IronPort AsyncOS 7.1 for Email Configuration Guide
OL-22158-02
Cisco Registered Envelope Service (hosted key service)
Step 4
If you select the Cisco Registered Envelope Service, enter the URL for the hosted 
key service. The key service URL is 
https://res.cisco.com
.
Step 5
If you select the IronPort Encryption appliance (local key service), enter the 
following settings:
Internal URL. This URL is used by the IronPort Email Security 
appliance to contact the in-network IronPort Encryption appliance.
External URL. This URL is used when the recipient’s message accesses 
keys and other services on the IronPort Encryption appliance. The 
recipient uses this URL to make inbound HTTPS requests.
Step 6
In the Envelope Settings section, select the level of message security:
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.
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, but the read receipts, Secure Reply, Secure Reply 
All, and Secure Message Forwarding features will be unavailable to 
prevent another email user from sending a message on behalf of the 
original recipient. 
Step 7
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:
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 8
Optionally, enable read receipts. If you enable this option, the sender receives a 
receipt when recipients open the secure envelope.
Step 9
Optionally, 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.
Step 10
Optionally, select an encryption algorithm:
ARC4. ARC4 is the most common choice, providing strong encryption 
with minimal decryption delays for message recipients.