DNS records are critical for the Domain Name System to work without problems. They all accomplish different tasks. Missing or mistaking a single DNS record configuration will certainly cause problems. Let’s see how essential the MX record is.
What’s the MX record for?
The mail exchange or MX record is in charge of storing the necessary information to know which mail server must get the emails traveling to a specific domain name.
Can you guess the number of emails that are sent every hour via the Internet? And how all of them can be delivered to their correct recipient?
How to create a DNS MX record?
Well, there are different actors and steps involved in this task (like the Simple Mail Transfer Protocol or SMTP). The mail exchange record is essential in the last step because knowing which mail server must receive the emails points out the correct route for messages to reach their destination.
Domain names usually have multiple MX records as a backup measure. The idea is to set up different TTL values for them. Then, in case a server fails, another resolver’s cache will work.
Why is the MX record essential?
Let’s start with a simple answer. MX record is essential because, without it, you won’t receive emails. Yes, you could lose all the emails sent to your domain name because the sender servers won’t know where to deliver them.
Now, let’s go deeper. The MX record contains very important information. It has the server’s hostname responsible for the management of the domain’s messages and a useful numeric value used for prioritization.
This value indicates the order for your mail servers to receive the messages. Rephrasing it, this prioritization value defines which mail server to connect first (second, third, etc.) to deliver your incoming messages. The higher the value is, the lower the priority and the opposite. For instance, an MX record set up with the number 2 will tell that its server has considerably more priority than another MX record holding the number 10.
You can create backups by setting up a second or third MX record with the same numeric value. This means they will share the same level of priority to receive emails. In this scenario, sender servers will randomly choose (from these choices) the server to deliver the messages.
The zero value is the most used, and it points out the highest priority level. An mail exchange record set up with the zero value points the Primary server that must get your emails.
To complete the route for emails to be delivered, MX records work with the A and AAAA DNS records. These last map a domain name to its corresponding IP address.
Conclusion
Yes, the MX record is essential! To miss an email can mean losing a business!
Having MX records, no matter from where on Earth people send emails to your domain, you will be able to receive them without trouble. What is very important is to ensure your MX records are well configurated.