Cisco Cisco Email Security Appliance C680 Guía Del Usuario

For information needed to complete these prerequisites, see 

Determine whether you will use custom or received headers to identify the IP address of the original 
external sender. 

If you will use custom headers: 

Determine the exact header that will label the originating IP address of relayed messages. 

For each MX, MTA, or other machine that connects to original external senders, set up that 
machine to add the header name and the IP address of the original external sender to incoming 
messages. 

Select Network > Incoming Relays. 

Click Add Relay. 

Enter a name for this relay.

Enter the IP address of the MTA, MX, or other machine that connects to the Email Security appliance to 
relay incoming messages. 

You can use IPv4 or IPv6 addresses, standard CIDR format, or an IP address range. For example, if you 
have several MTAs at the edge of your network receiving email, you might want to enter a range of IP 
addresses to include all of your MTAs, such as 10.2.3.1/8 or 10.2.3.1-10. 

For IPv6 addresses, AsyncOS supports the following formats:

2620:101:2004:4202::0-2620:101:2004:4202::ff

2620:101:2004:4202::

2620:101:2004:4202::23

2620:101:2004:4202::/64

Specify the header that will identify the IP address of the original external sender. 

When entering a header, you do not need to enter the trailing colon. 

Select the header type: 

Choose custom headers (recommended) or Received headers. 

For custom headers: 

Enter the header name that you configured the relaying machine to add to relayed messages. 

For example: 

SenderIP 

or 

X-CustomHeader 

For Received headers: 

Enter the character or string after which the IP address will appear. Enter the number for the “hop” 
to check for the IP address. 

Submit and commit your changes.