Cisco Cisco Email Security Appliance C160 Mode D'Emploi

If you enable envelope sender verification or disable allowing partial domains in 
SMTP Address Parsing options for a listener, the default domain settings for that 
listener will no longer be used.

These features are mutually exclusive.

Determines behavior if source routing is detected in 
the “MAIL FROM” and “RCPT TO” addresses. 
Source routing is a special form of an email address 
using multiple ‘@’ characters to specify routing (for 
example: @one.dom@two.dom:joe@three.dom). If 
set to “reject,” the address will be rejected. If “strip,” 
the source routing portion of the address will be 
deleted, and the message will be injected normally.

discar
d

Usernames that include characters (such as % or !, for 
example) entered here will be rejected.

none

Determines behavior for when an address literal is 
received that the system can not handle. Currently, 
this is everything except for IPv4. Thus, for example, 
for an IPv6 address literal, you can either reject it at 
the protocol level, or accept it and immediately hard 
bounce it.

Recipient addresses containing literals will cause an 
immediate hard bounce. Sender addresses may get 
delivered. If the message cannot be delivered, then 
the hard bounce will hard bounce (double hard 
bounce).

In the case of reject, both sender and recipient 
addresses will be rejected immediately at the 
protocol level.

reject