How to migrate MXs

DNS Records Overview

A DNS (Domain Name System) name provides a way to easily identify a host zone with a name that is easier for a physical person to remember and interpret than raw IP addresses.

A DNS name is associated with one or several IP addresses. This configuration is carried out by the Registrar: The entity that hosts the domain.

The name example.com is associated with the IP address 93.184.216.34.

Note: DNS records also provide additional configuration elements, such as setting the destination for emails, SPF field, etc.

Setting up DNS record for email routing

When a mail server sends an email, it sends a DNS request to retrieve the MX (Mail Exchanger) fields from the domain name of the recipient.

In the example below, the MX fields are displayed as follows for the domain mail75.com:

mail75.com  MX preference = 10, mail exchanger = mx01.cloud.vadesecure.com
mail75.com  MX preference = 10, mail exchanger = mx02.cloud.vadesecure.com
mail75.com  MX preference = 10, mail exchanger = mx03.cloud.vadesecure.com
mail75.com  MX preference = 10, mail exchanger = mx04.cloud.vadesecure.com

Understanding the DNS record

The above example is given for a DNS record of type MX and composed as follows:

DNS Zone (mail75.com): This is the DNS Zone the parameter applies to.
Weight (10): This is the weight of precedence for the MX field. The weight allows distributing the load of the email traffic between various DNS entries. The lowest weight will be the path that emails will take as a priority. Entering two equal weights allows sharing the email traffic load equally between the hosts.
Hostname (mx01.cloud.vadesecure.com, mx02.cloud.vadesecure.com, mx03.cloud.vadesecure.com or mx04.cloud.vadesecure.com): These are the names of the hosts to which emails for the domain mail75.com will be sent. You may enter either an IP address or a hostname in this field. The host name is recommended to reduce the impact of changing the IP address range of the hosts.

Looking up the MX fields for a domain

To find out which MX fields are associated with a domain, you may run the following commands in a terminal:

On Windows:

# nslookup -type=mx example.com

On Linux

$ dig mx example.com

Important: MX fields updates are propagated progressively. Disruption to or loss of emails should not be expected. For a certain amount of time after the modifications are made, emails may still be routed to the former MXs, and the new ones simultaneously. As they continue to propagate, DNS servers from the Internet will use the new route to eventually route all emails for that domain to Vade Cloud™. The propagation time depends on the TTL value defined at the DNS level.

Setting up a DNS record for SPF

SPF (for Sender Policy Framework) DNS records allow domain owners to provide a list of authorized IP addresses, aiming to prevent forgery of domain-issued emails from malicious senders.

The SPF field is a specific type of DNS record, which uses a DNS record of type TXT attached to the domain. This field includes the IP addresses or hostnames of servers that are allowed to send email traffic with the domain name as the sender.

If the protected domain name has corresponding SPF records, filtering the outbound emails with Vade Cloud™ requires the SPF record to be modified to add the Vade servers.

You need to add the following SPF field to your DNS records:

v=spf1  include:spf.cloud.vadesecure.com -all

In the examples above, only Vade Cloud™ servers are allowed to send emails using the domain name as the sender.

Looking up the SPF field for a domain

To find out the SPF field for a given domain (if it exists), you may run the following commands in a terminal:

On Windows

# nslookup -type=txt vadesecure.com

On Linux

$ dig txt vadesecure.com

Adding a DNS record to use Vade Cloud

You must add a new DNS record or modify the existing MX record after you have configured your domain on the Vade Cloud™ administration interface so that the email traffic gets routed to the Vade Cloud™ platform in the future.

To do so, you will need to add the following MX hostnames to your DNS record:

mx01.cloud.vadesecure.com
mx02.cloud.vadesecure.com
mx03.cloud.vadesecure.com
mx04.cloud.vadesecure.com

Note: Ask your Registrar for the steps to follow on his domain management console to update your DNS records.