Configuring Your Local Network DNS server

Before your mail server can communicate with other mail hosts, you must configure the DNS server to recognize your mail server. Without a functional and correctly set DNS, IMail Server cannot deliver mail, except to domains that are within IMail Server.

For each mail host on your network, you must make the following entries in your DNS:

• An MX record for the mail domain (for example, domain.com). The MX record identifies the host name of the mail host. Note that mail hosts (virtual hosts) that do not have an IP address require only an MX record.
• An A record for the host name of the mail host. The A record maps a host name to an IP address.
• A PTR record for the IP address of the mail host. The PTR record maps an IP address to the host name and is used for reverse lookups.
• An SPF record lets other email servers use SPF filtering (if the feature is available on the mail server) to protect against incoming email from forged (spoofed) email addresses that may be associated with your mail server. As SPF records are implemented more widely, SPF filtering will become more effective at identifying spoofed email messages. For more information about SPF records, see the IMail Administrator Help.

Since there are DNS servers from many vendors available, we cannot describe how to create the records for your specific DNS server. Instead, we show an example using a basic configuration for a single mail host.