MX Record a short for Mail Exchanger Record. The Domain Name System uses it to associate a particular domain name with emails, so that when someone sends an email to your domain, the MX records route it to the correct server so that you can retrieve it.
You don’t need to limit yourself to one MX record. You can have many which point to other servers (typically backup servers) to ensure that your emails will get through if one of them fails. So, the single domain can use many email servers, making your emails more secure and ensuring that they get you quicker. An MX record is always needed to send email via the Internet, and they come pre-configured when you register your domain.
You can edit existing MX records or create new ones by going to your domain name provider and typing your domain name into the name field in the DNS settings of your control panel.
The Type field should always be set to MX. The Class field should say IN (Internet), and the TTL should be in seconds. TTL means “Time to Live” and shows how much time is needed to update a record.
The Priority (Preference) field will be important when you create additional MX records, because it lets you assign different priorities to servers, so that when one of them isn’t working, request will always be passed onto the next one. The highest-ranking email server will be contacted first, and if that doesn’t work then it’s on to the next.
Lastly, the Data/Server field displays the hostname of your domain’s mail server.