An MX record (Mail Exchanger) tells the internet which server should handle incoming email for your domain. If this record is set up incorrectly, no email will come in, even if your website works perfectly fine. In this article, you’ll read exactly what an MX record does, how to set one up yourself, and how to check whether everything is configured correctly.
What is an MX record?
An MX record is a line in your domain’s DNS settings that indicates which mail server incoming email should be sent to. Without a correct MX record, the internet simply doesn’t know where an email for [email protected] should go. An MX record always consists of two important parts:
- Hostname: the mail server the email is sent to, for example mail.yourdomain.com.
- Priority: a number that determines which server is tried first if you have multiple MX records. The lower the number, the higher the priority.
You can set up multiple MX records as a backup: if the primary server is unreachable, email automatically tries the server with the next lowest priority.
Setting up an MX record: step by step
Below you’ll find the general steps for setting up an MX record. The exact screens differ per DNS management environment, but the principles are the same everywhere.
Find your DNS management
Log in with the party where your domain is registered, or with your hosting provider if they also manage your DNS. Go to the DNS management or DNS zone of your domain.
Add a new MX record
Click ‚add record‘ and choose MX as the type. Under host or name, you usually enter an @ (for the main domain), and under value, enter the hostname of your mail server.
Set the priority
Give your main mail server a low priority, for example 10. If you have a backup server, give it a higher number, for example 20.
Remove old or unnecessary MX records
Did you previously host with another provider? Then remove the old MX records, otherwise email can get confused about where it should go.
Save and wait for propagation
DNS changes aren’t immediately known everywhere. It can take some time before the change is visible worldwide. After that, test whether email arrives properly.
Common mistakes
Things regularly go wrong when setting up an MX record. Watch out for these common pitfalls:
- Incorrect hostname: a typo in the mail server name means email doesn’t arrive anywhere.
- Forgetting to remove old records: this can cause email to sometimes try the wrong (old) server first.
- MX record pointing to an IP address instead of a hostname: an MX record must always point to a hostname, not an IP address.
- No trailing dot after the hostname: in some DNS systems, you need to add a dot after the hostname (for example mail.domain.com.) to indicate it’s a fully qualified domain.
- Confusing A records and MX records: an MX record handles email, an A record handles where your website points to. These are two separate matters.
Not sure about your current domain settings? Also check your domain names management to see if everything is properly in order.
Checking whether your MX record works
After setting up the MX record, you naturally want to know whether it actually works. You can check this in a few ways:
- Online MX lookup tools: there are free tools where you enter your domain name and immediately see which MX records are active and at what priority.
- Command line: on Windows, Mac, and Linux, you can use a simple command (for example nslookup or dig, followed by -type=mx and your domain name) to directly see which MX records are active.
- Send a test email: send a test email from an external email address to your own domain and check whether it arrives.
If you don’t see a record or see an outdated one, wait a bit longer: DNS changes need time to become visible everywhere. If the problem persists longer, check again whether you saved the setting correctly.
Frequently asked questions
How long does it take before an MX record is active?
This depends on DNS propagation and can vary from a few minutes to a few hours. Sometimes it takes longer, depending on previously set cache times.
Can I use multiple MX records at the same time?
Yes, this is often done as a backup. The server with the lowest priority (the lowest number) is tried first.
What’s the difference between an MX record and an A record?
An MX record determines where incoming email goes, an A record determines where your domain name points to, for example your website. These are two separate settings in your DNS.
Why isn’t my email arriving even though the MX record appears to be set correctly?
Also check whether there are no old, unnecessary MX records still active and whether your mail server itself is configured correctly. Sometimes the problem also lies with spam filtering or SPF/DKIM settings.
Conclusion
A correctly set up MX record is essential for receiving email on your own domain. Make sure the hostname is correct, set the right priority, and remove old records. Then check with a lookup tool or test email whether everything works. Not sure about your settings? Check out your options for web hosting with correctly configured DNS settings.