What is an MX Record? How to Properly Configure Mail Server Redirection?

Email communication is an indispensable part of today's digital world. Businesses and individuals communicate, exchange information, and perform various transactions via email. One of the critical elements that ensures emails reach recipients correctly and reliably is the MX (Mail Exchange) record. In this article, we will examine in detail what an MX record is, how it works, and how it should be configured for proper mail server redirection.

What is an MX Record and Why is it Important?

An MX record is a DNS (Domain Name System) record that specifies which mail servers will handle the email traffic for a domain name. In other words, when someone sends you an email, the sender's mail server first checks the MX record of the recipient's domain name. This record specifies which server the email should be delivered to. Without an MX record, emails cannot reach the correct server and cannot be delivered to the recipient. Therefore, a properly configured MX record is vital for email communication to function smoothly.

The importance of MX records can be summarized as follows:

Email Deliverability: Correct MX records ensure that emails reach the correct server and land in the recipient's inbox.
Reliability: MX records verify that your email server is authorized and that emails come from a trusted source.
Redundancy: By using multiple MX records, you can ensure that emails are redirected to backup servers if the primary mail server fails.
Spam Control: MX records help with spam filtering by making it difficult for spammers to impersonate your email server.

How Does an MX Record Work?

When an email is sent, the process involves the following steps:

The sender creates and sends an email using the recipient's email address (e.g., [email protected]).
The sender's mail server queries the DNS records of the recipient's domain name (exampledomain.com).
The DNS server returns the MX records of the domain name. The MX records contain a list of mail servers and the priority value of each server.
The sender's mail server attempts to connect to the mail server with the lowest priority value. The lower the priority value, the more preferred the server is.
If the primary server cannot be reached, the sender's mail server attempts to connect to the next server with a higher priority value.
When the connection is successful, the email is delivered to the recipient's mail server.
The recipient's mail server processes the email and places it in the recipient's inbox.

For example, let's say the following MX records are configured for the exampledomain.com domain name:


            exampledomain.com. IN MX 10 mail.exampledomain.com.
            exampledomain.com. IN MX 20 backup.exampledomain.com.

In this case, the sender's mail server will first attempt to connect to the mail.exampledomain.com server (priority 10). If this server cannot be reached, it will attempt to connect to the backup.exampledomain.com server (priority 20).

How to Configure an MX Record?

MX record configuration is usually done from the control panel of your domain name registrar or DNS provider. The process may vary depending on the provider, but the basic steps are generally the same:

Log in to your domain name registrar or DNS provider.
Go to the DNS management section of your domain name.
Find the MX records section. This section is usually named "Mail Exchange Records" or something similar.
Add a new MX record or edit an existing record.
Enter the following information:
- Domain Name: Usually your domain name (e.g., exampledomain.com) or the @ symbol is used.
- Record Type: Select MX.
- Priority: A number that determines the priority of the mail server. A lower number means higher priority. Values such as 10, 20, 30 are commonly used.
- Mail Server: The fully qualified domain name (FQDN) of the mail server. For example, mail.exampledomain.com. This is the address of the server to which emails will be delivered.
- TTL (Time To Live): A value that specifies how long the record will be cached. Values such as 3600 seconds (1 hour) or 86400 seconds (1 day) are commonly used.
Save the record.
It may take some time for the changes to take effect (DNS propagation). This period usually varies between a few minutes and a few hours.

Important Notes:

When using multiple MX records, assign different priority values to each server.
Make sure the mail server domain name is correct and working.
Since DNS changes may take some time to propagate, do not try to send emails immediately after making changes. Wait a few hours and then check the accuracy by sending test emails.

Example MX Record Configuration

Below are example MX record configurations for different scenarios:

Using a Single Mail Server

If you are using only one mail server, you can configure an MX record as follows:


            exampledomain.com. IN MX 10 mail.exampledomain.com.

This means that all emails will be routed to the mail.exampledomain.com server.

Using a Backup Mail Server

You can increase the reliability of email communication by using a backup mail server. You can use a configuration like the following:


            exampledomain.com. IN MX 10 mail.exampledomain.com.
            exampledomain.com. IN MX 20 backup.exampledomain.com.

In this configuration, emails are primarily routed to the mail.exampledomain.com server. If this server is unreachable, it is routed to the backup.exampledomain.com server.

Using a Third-Party Email Service (e.g., Google Workspace or Microsoft 365)

If you are using a third-party email service such as Google Workspace or Microsoft 365, you need to use the MX records provided by your provider. These records usually look like this:


            exampledomain.com. IN MX 1 ASPMX.L.GOOGLE.COM. 1
            exampledomain.com. IN MX 5 ALT1.ASPMX.L.GOOGLE.COM.
            exampledomain.com. IN MX 5 ALT2.ASPMX.L.GOOGLE.COM.
            exampledomain.com. IN MX 10 ALT3.ASPMX.L.GOOGLE.COM.
            exampledomain.com. IN MX 10 ALT4.ASPMX.L.GOOGLE.COM.

When you add these records to your domain's DNS settings, your emails will be routed through Google Workspace servers.

Troubleshooting MX Record Issues

If you are experiencing problems with MX record configuration, you can troubleshoot by following these steps:

Check MX Records: Check your MX records using tools like nslookup or dig. Make sure they are configured correctly.
Check DNS Propagation: It may take some time for DNS changes to propagate worldwide. You can use online tools to check DNS propagation.
Check Mail Server Settings: Make sure your mail server is configured correctly and is compatible with your MX records.
Check Spam Filters: If your emails are landing in the spam folder, check the spam filters and configure SPF and DKIM records if necessary.
Contact Your Domain Provider: If you cannot resolve the issues, contact your domain provider for assistance.

Conclusion and Summary

The MX record is a fundamental part of email communication, and its correct configuration ensures that emails are delivered reliably and smoothly. In this article, we have examined in detail what an MX record is, how it works, how to configure it, and troubleshooting methods. By configuring the correct MX record, you can increase the reliability and efficiency of your email communication. Remember, if you are using a third-party email service, you must use the MX records provided by your provider.