Руководство Пользователя для Cisco Cisco Email Security Appliance X1070
Chapter 4 Validating Recipients Using an SMTP Server
4-8
Cisco IronPort AsyncOS 7.5 for Email Advanced Configuration Guide
OL-25137-01
Call-Ahead Server
Type
Type
Choose from one of the following methods for connecting
to the call-ahead server:
to the call-ahead server:
•
Use Delivery Host. Select this option to specify that
the host for the delivery email address is used for the
SMTP call-ahead query. For example, if the mail
recipient address is recipient@example.com, the
SMTP query is executed against the SMTP server
associated with example.com. If you have configured
SMTP routes or LDAP routing queries, these routes are
used to determine the SMTP server to query. For
details about configuring LDAP routing queries, see
the host for the delivery email address is used for the
SMTP call-ahead query. For example, if the mail
recipient address is recipient@example.com, the
SMTP query is executed against the SMTP server
associated with example.com. If you have configured
SMTP routes or LDAP routing queries, these routes are
used to determine the SMTP server to query. For
details about configuring LDAP routing queries, see
.
•
Static Call-Ahead Server. Use this option to create a
static list of call-ahead servers to query. You may want
to use this option if you do not expect the names and
locations of the call-ahead servers to change often.
When you use this option, the Email Security
appliance queries the hosts in a round-robin fashion,
starting with the first static call-ahead server listed.
static list of call-ahead servers to query. You may want
to use this option if you do not expect the names and
locations of the call-ahead servers to change often.
When you use this option, the Email Security
appliance queries the hosts in a round-robin fashion,
starting with the first static call-ahead server listed.
Note
Note that when you choose the static
call-ahead server type, no SMTP routes are
applied to the query. Instead an MX lookup is
performed, and then an A lookup is performed
on the hosts to obtain the call-ahead IP
addresses for the static servers.
call-ahead server type, no SMTP routes are
applied to the query. Instead an MX lookup is
performed, and then an A lookup is performed
on the hosts to obtain the call-ahead IP
addresses for the static servers.
Static Call-Ahead
Servers
Servers
If you choose to use the static call-ahead server type, enter
a list of host and port combinations in this field. List the
server and port using the following syntax:
a list of host and port combinations in this field. List the
server and port using the following syntax:
ironport.com:25
Separate multiple entries with a comma.
Table 4-1
SMTP Call-Ahead Server Profile Settings
Setting
Description