Adding a DNS Black List to the Email Domain
Use this dialog to enable DNS black lists for the mail domain. In order for a black list to appear in this list, it must be configured for the server. If no black lists are displayed, see DNS black lists for information on how to configure DNS black lists for the server.
- Enter a name in the text box to identify the black list. This can be any name that you want, and will be used in log lines to identify the black list entry.
- In the text box, enter the domain name or IP address of the DNS server to contact for black list queries. This field contains an asterisk (*) by default, which indicates that the default IMail Server DNS is used for black list queries, where it relays the DNS query to the DNS server for the black list. Using the asterisk eliminates the need to enter the IP address or domain.
- In the text box, enter the domain to query in the zone file of the black list. This name usually matches the server domain name. However, sometimes a black list will contain multiple zones to query on the same server. When this happens, the server name and the query domain will be different. The only way to know this is to read the documentation for the black list being used.
- Select the type of lookup that the black list performs from the list box.
- This type of black list uses a message's "FROM" address to determine whether the message is spam.
- This type of black list checks the IP address of the connecting SMTP server against spam databases to determine whether the message is spam. If the IP address is listed in one of the black list's databases, the message is identified as spam.
- This type of black list checks the domain supplied in the HELO or EHLO command to determine whether to accept the message. The hostname that is given in the HELO/EHLO command must match the IP address.
- This type of black list checks the information following the @ symbol supplied in the "MAIL FROM" command to determine whether the message is spam.
- Select the check box to determine whether hosts can use the black list. When enabled, the black list appears in the dialog box for a host. If this option is cleared, the black list is not displayed on the dialog box for the host, but will still be displayed at the server level.
- Some black lists, especially ones that supply .txt records, have packets that are too large to transmit via the UDP protocol. These lists disable UDP access and require TCP to query the black list. Select this check box to allow the administrator to flag a list as one of these types.
- Click this button to add the new black list. Your new black list appears on the DNS Black Lists page.
- Click this button to cancel adding a new black list. No new information should appear on the DNS Black Lists page.
Related Topics
Setting DNS Black Lists Options
Setting White List Administration Options
Setting IMail SMTP Control Access Options