ZyXEL ZyWALL ATP700 User Guide - Page 622

Chapter 31 Email Security Table 240 Configuration > Security Service > Email Security LABEL DESCRIPTION Action taken when mail sessions threshold is reached An email session is when an email client and email server (or two email servers) connect through the Zyxel Device. Select how to handle concurrent email sessions that exceed the maximum number of concurrent email sessions that the email security feature can handle. See the chapter of product specifications for the threshold. Select Forward Session to have the Zyxel Device allow the excess email sessions without any spam filtering. Query Timeout Settings SMTP Select Drop Session to have the Zyxel Device drop mail connections to stop the excess email sessions. The email client or server will have to re-attempt to send or receive email later when the number of email sessions is under the threshold. Select how the Zyxel Device is to handle SMTP mail query timeout. Select drop to discard SMTP mail. Select forward to allow SMTP mail to go through. POP3 Select forward with tag to add a tag to an SMTP query timeout mail's mail subject and send it on to the destination. Select how the Zyxel Device is to handle POP3 mail query timeout. Select forward to allow POP3 mail to go through. Timeout Value Timeout Tag Timeout X-Header DNSBL Settings Max. IPs Checking Per Mail IP Selection Per Mail Select forward with tag to add a tag to an POP3 query timeout mail's mail subject and send it on to the destination. Set how long the Zyxel Device waits for a reply from the mail scan server. If there is no reply before this time period expires, the Zyxel Device takes the action defined in the relevant Actions when Query Timeout field. Enter a message or label (up to 15 ASCII characters) to add to the mail subject of emails that the Zyxel Device forwards if queries to the mail scan servers time out. Specify the name and value for the X-Header to be added when queries to the mail scan servers time out. Set the maximum number of sender and relay server IP addresses in the mail header to check against the DNSBL domain servers. Select first N IPs to have the Zyxel Device start checking from the first IP address in the mail header. This is the IP of the sender or the first server that forwarded the mail. Apply Reset Select last N IPs to have the Zyxel Device start checking from the last IP address in the mail header. This is the IP of the last server that forwarded the mail. Click Apply to save your changes back to the Zyxel Device. Click Reset to return the screen to its last-saved settings. 31.4 The Black List / White List Screen Click Configuration > Security Service > Email Security > Black /White List to display the Black List / White List screen. Configure the black list to identify spam email. You can create black list entries based on the sender's or relay server's IP address or email address. You can also create entries that check for particular email header fields with specific values or specific subject text. Click a column's heading cell to sort the table entries by that column's criteria. Click the heading cell again to reverse the sort order. ZyWALL ATP Series User's Guide 622