Overview

An MX (mail exchange) record is an entry in your DNS zone file which specifies a mail server to handle a domain's email. You must configure an MX record to receive the email to your domain.

Note: If you are using Kerio Connect as an internal email system, with no communication outside of your domain, it's not necessary to configure an MX record for your domain. You may configure any domain in Kerio Connect, as it does not perform any DNS validation of its local domain names.

Solution

1. To receive an email outside of your locally configured domains, ensure that the underlying operating system properly resolves domain names. This means that a valid domain name server must be configured in the TCP/IP settings of the host operating system.
2. Configure the MX record on the authoritative name server for your domain:
   • In most cases, the authoritative name server is the DNS servers managed by your domain registrar. For example, Godaddy or Network Solutions.
     
   • These domain registrars usually provide additional services, including DNS hosting. In this case, you will use a web-based DNS configuration utility to configure your MX record.
   • Check Godaddy and Network Solutions to configure the MX record.
   • Since most DNS servers store the information in a cache for a certain period of time, it might take up to 24 hours for the change to get propagated over the internet to DNS servers where the record is stored. Email delivery can be pointed to the secondary email server in the MX record list until the primary server DNS name is changed.
   • If a secondary domain is created in Kerio Connect, the MX record needs to be pointed towards the internet hostname of Kerio Connect, e.g. mail.primary-domain.com

3. Check if the DNS server applied the MX record changes by using nslookup command-line tool:
   • Type nslookup.
   • Type set q=MX.
   • Type Domain name.
   • The MX records, authoritative, and non-authoritative answers will be displayed.

Confirmation

You can check a DNS MX record using an online test tool (e.g. MXtoolbox) or by using nslookup command-line tool. The nslookup tool also accepts the following format:
nslookup www.testsite.com ns40.domaincontrol.com

In the example below, three servers can receive emails for the kerio.com email domain. The lowest number means the highest server preference. In this example the primary MX server (the server with the highest preference) is mx1.kerio.com: