Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

Check firewall permissions. 

The appliance may need all of the following ports to be opened in order to function properly: ports 
20, 21, 22, 23, 25, 53, 80, 123, 443, and 628. (See 

Send email from the appliance on your network to 

dnscheck@ironport.com

Send an email from within your network to 

dnscheck@ironport.com

 to perform basic DNS checks 

on your system. And auto-responder email will respond with the results and details of the following 
four tests: 

DNS PTR Record - Does the IP address of the Envelope From match the PTR record for the 
domain? 

DNS A Record - Does the PTR record for the domain match the IP address of the Envelope From? 

HELO match - Does the domain listed in the SMTP HELO command match the DNS hostname in 
the Envelope From? 

Mail server accepting delayed bounce messages - Does the domain listed in the SMTP HELO 
command have MX records that resolve IP addresses for that domain? 

If you suspect problems with injecting email, use the following strategies:

Confirm the IP address that you are injecting from, and then use the 

listenerconfig

 command to 

check for allowed hosts.

Is the IP address allowed to connect to the listener you have created? Use the 

listenerconfig

 

command to examine the Host Access Table (HAT) for the listener. Use these commands to print the 
HAT for a listener:

listenerconfig

 -> 

edit

 -> listener_number -> 

hostaccess

 -> 

print

 

The HAT can be configured to refuse connections by IP address, block of IP addresses, hostname, 
or domains. For more information, see “Specifying Hosts that are Allowed to Connect” on page 107. 

You can also use the 

limits

 subcommand to check the maximum number of connections allowed 

for a listener:

listenerconfig

 -> 

edit

 -> listener_number -> 

limits

On the machine that you are injecting from, use Telnet or FTP to manually connect to the appliance. 
For example:

You can also use the 

telnet

 command within the appliance itself to connect from the listener to the 

actual appliance:

injection_machine% telnet appliance_name

mail3.example.com> telnet

Please select which interface you want to telnet from.

1. Auto