Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

 and 

 provide an overview of how email is routed through the system, from 

reception to routing to deliver. Each feature is processed in order (from top to bottom) and is briefly 
summarized. Shaded areas in 

 represent processing that occurs in the Work Queue. 

You can test most of the configurations of features in this pipeline using the 

trace

 command. For more 

information, see “Debugging Mail Flow Using Test Messages: Trace” in the Troubleshooting chapter.

For outgoing mail, RSA Email Data Loss Prevention scanning takes place after the Outbreak Filters 
stage.

ACCEPT, REJECT, RELAY, or TCPREFUSE connections

Maximum outbound connections

Maximum concurrent inbound connections per IP address

Maximum message size and messages per connection

Maximum recipients per message and per hour

TCP listen queue size

TLS: no/preferred/required

SMTP AUTH: no/preferred/required

Drop email with malformed FROM headers

Always accept or reject mail from entries in the Sender Verification Exception Table.

SenderBase on/off (IP profiling/flow control) 

Adds a received header to accepted email: on/off.

Adds default domain for “bare” user addresses.

Used to verify incoming bounce messages as legitimate.

Rewrites the Envelope Recipient for each recipient in a message that matches a domain 
in the domain map table. 

(Public listeners only) ACCEPT or REJECT recipients in 

RCPT TO 

plus Custom SMTP 

Response. Allow special recipients to bypass throttling. 

Rewrites the Envelope Recipient. (Configured system-wide. 

aliasconfig

 is not a 

subcommand of 

listenerconfig

.)

LDAP validation for recipient acceptance occurs within the SMTP conversation. If the 
recipient is not found in the LDAP directory, the message is dropped or bounced. LDAP 
validation can be configured to occur within the work queue instead.