MX Records

When email is sent to a domain name, the sending party's email provider will perform an MX record lookup on the domain name following the @ sign. For instance, if you were to send a message to linode@example.net, your email provider would look up the MX records for the domain example.net.

Your third-party email provider should provide you a number of mail server names, which may look something like this:

10 mail1.linode.example
20 mail2.linode.example

These mail server names may contain an associated number, as in this example. These numbers are referred to as the priority of each mail server, defining which mail servers are more favored for mail delivery. You may also see a number of other synonyms for this value, such as distance or preference.

No matter the name of this value, it works the same: the lower the priority value, the more favored the mail server. For the example mail servers listed above, mail1.linode.example has a priority of 10, while mail2.linode.example has a priority of 20. Since 10 is less than 20, this mail server will be preferred for receiving mail.

What is the reason for defining priority? It helps add redundancy to your MX record setup. Defining a backup MX record on your domain name with a higher priority will ensure that you can receive mail directed to your domain even if one of your mail servers goes down. Without an additional working record, mail sent to your domain will become undeliverable. For this reason, it is very important that you define at least two mail servers on your domain. Any responsible email provider will recognize the importance of this setup and should provide you at least two mail servers for your domain.

One last detail worth noting about priority is that you can use it for load balancing. This is accomplished by having two MX records for two different mail servers, but which share the same priority. You may come across this setup with certain mail providers in case you are surprised to see two MX record with equal priority values.

Last but not least, it is important to make sure that the MX records you receive from your third-party email provider contain hostnames as opposed to IP addresses. While it may work to define an MX records defining an IP address, your email will become undeliverable if your email provider changes the IP address of its mail server. Email providers will automatically query the A/AAAA records of the hostnames defined in MX records to resolve those hostnames to IP address(es).

Adding MX records through Linode DNS Manager

To define MX records for your domain so that you can receive mail at your Linode-managed domain, navigate to your Domains in Cloud Manager, add or select your domain, then proceed to create a new MX record for your domain.

You will need to define an MX record for each mail server you were provided by your third-party email provider. For each record, you will need to define the following values:

• Mail server: the mail server, such as mail1.linode.example in the above example
• Preference: the priority value, such as 10
• TTL: you can adjust this depending on how often you would like your records to update
• Subdomain: if you want to receive email at a subdomain of your domain as you initially defined it in DNS Manager, put that subdomain in this field. For example, if you defined your domain name as example.net and want to receive email at mail.example.net, you would place mail in this field. Most likely, you will want to receive email directly at example.net, in which case you should leave this field blank to ensure proper mail delivery.

Once you ensure the accuracy of your settings, click the Save button to update your DNS records. You may need to wait up to 24 hours for your DNS changes to propagate around the world, but once they do, you should be able to receive email sent to your domain.

Important limitations to note

Linode's DNS Manager requires at least one billable service be present on the account before it will return DNS records. It is a good idea to ensure that the credit card information on file with your account is accurate and to pay your account's bills in a timely fashion to ensure that your services do not go uninterrupted.

It is also a good idea to avoid the temptation to define an email address set up through Linode's DNS Manager as the email address on file with your account. This will ensure that you do not create a single point of failure when we attempt to send you important communications regarding your account.