Cisco Cisco Email Security Appliance C170 Guia Do Utilizador
4-5
Cisco IronPort AsyncOS 7.6 for Email Advanced Configuration Guide
OL-25137-01
Chapter 4 Validating Recipients Using an SMTP Server
Call Ahead Server Responses
The SMTP server may return the following responses:
•
2xx: When an SMTP code starting with 2 is received from the call-ahead server, the recipient is
accepted. For example, a response of 250 allows the mailing action to continue.
accepted. For example, a response of 250 allows the mailing action to continue.
Table 4-2
SMTP Call-Ahead Server Profile Advanced Settings
Setting
Description
Interface
The interface used to initiate the SMTP conversation with the SMTP server.
Choose to use the Management interface or Auto. When you select Auto, the
Email Security appliance attempts to automatically detect an interface to
use. The Cisco IronPort interface attempts to connect to the SMTP server in
the following ways:
Email Security appliance attempts to automatically detect an interface to
use. The Cisco IronPort interface attempts to connect to the SMTP server in
the following ways:
•
If the call-ahead server is on the same subnet as one of the configured
interfaces, then the connection is initiated by the matching interface.
interfaces, then the connection is initiated by the matching interface.
•
Any configured SMTP routes are used to route the query.
•
Otherwise, the interface that is on the same subnet as the default
gateway are used.
gateway are used.
MAIL FROM Address
The MAIL FROM: address to be used for the SMTP conversation with the
SMTP server.
SMTP server.
Validation Request Timeout
The number of seconds to wait for a result from the SMTP server. This
timeout value is for a single recipient validation request which may involve
contacting multiple call-ahead servers. See
timeout value is for a single recipient validation request which may involve
contacting multiple call-ahead servers. See
Validation Failure Action
The action to be taken when a recipient validation request fails (due to a
timeout, server failure, network issue, or unknown response). You can
configure how you want the Email Security appliance to handle the different
responses. See
timeout, server failure, network issue, or unknown response). You can
configure how you want the Email Security appliance to handle the different
responses. See
.
Temporary Failure Action
The action to be taken when a recipient validation request temporarily fails
(and a 4xx response is returned from the remote SMTP server). This can
occur when the mailbox is full, the mailbox is not available, or the service
is not available).
(and a 4xx response is returned from the remote SMTP server). This can
occur when the mailbox is full, the mailbox is not available, or the service
is not available).
See
.
Max. Recipients per
Session
Session
Maximum number of recipients to be validated in a single SMTP session.
Specify between 1 - 25,000 sessions.
Max. Connections per
Server
Server
Maximum number of connections to a single call-ahead SMTP server.
Specify between 1-100 connections.
Cache
Size of the cache for SMTP responses. Specify between 100-1,000,000
entries
entries
Cache TTL
Time-to-live value for entries in the cache. This field defaults to 900
seconds. Specify between 60 - 86400 seconds.
seconds. Specify between 60 - 86400 seconds.