DNS records are what you need to protect yourself against spam and spam hosts!
With DNS records, you are protected from spam while ensuring that your server is not a spam host. In this post, you will learn what DNS records are, the different DNS record types, and which one is used for email servers.
Let’s get started!
What are DNS Records?
The domain name system (DNS) refers to a large-scale system of information containing the IP addresses, hosting, domain names, and other registration across each website on the internet. In the case of DNS records, they act as instructions for the DNS server. That way, it quickly determines which domain names every IP address is associated with.
These records come with a series of text files written in DNX syntax, a string of characters used as commands telling the DNS server what to do. Beware that all DNS records also have time-to-live (TTL) that indicates how often the server should refresh the record.
You can imagine those records like a business listing that provides a bunch of information about the business, including services or products offered, location, hours, etc. All domains should have at least a few DNS records to enable the users to access their site using a domain name.
Which Types of DNS Records Should You Know About?
Without DNS records, a website cannot operate correctly. These records act as a map telling the server which domain each IP address is associated with and how they should handle the received access requests.
While you can find various DNS records, below are the types that are commonly used, and you should know about:
Address (A) records help resolve the IP address. These host records connect the domains registered to the correct IP address. That way, a website resolves correctly once someone types in the website address.
A Canonical Name (CNAME) is responsible for pointing a single domain to a subdomain to another domain name. As a result, you can update a single A Record every time you make a change, no matter how many Host Records are required to resolve to that specific IP address.
A Mail Exchange (MX) record is quite different from other records. They are used to direct emails received by the custom addresses associated with a domain name, unlike other DNS records that resolve to destinations or texts of different IP addresses.
A Text (TXT) records were initially designed for human-readable text. Because of their dynamic quality, you can use them for several purposes. Generally, these records are utilized for Google verification. Beware that they are not used to drive traffic. Instead, they are being used to deliver the necessary information to external sources.
A PTR record refers to a reverse lookup mapping the IP address to the domain name. Since several mail servers do not trust any mails coming from a server unless it can make a reverse DNS lookup.
A SPF record provides mail servers a path to verify that a mail claim from a domain is from one IP address. It takes place by checking the special TXT record found in the DNS records. That way, mail spoofing is prevented.
AAA Records are similar to A Records. However, the difference is that AAA records enable you to point the domain to the IPv6 address.
What Type of DNS Record Is Used for Email Servers?
DNS records configuration is critical to ensure that mail servers will trust you to receive your mails and find you to send mails to your users. Below are the four different DNS records used for email servers:
These records serve similar purposes as A records. However, the hostnames are mapped to the IPv6 address that contains 128-bits as opposed to the IPv4 address’ 32-bits.
If you want to direct part of your site to the external link, you can use CNAME records. They enable the domain to resolve to a similar server, whether there is the www subdomain or not. They have also used to alias a hostname to another hostname. Once you request a record containing a CNAME, there will be a repetition of the DNS resolution process with the new hostname.
MX records tell the mail server the server name on the internet so that your domain will receive a mail. Since they can have any name, they are considered as free text fields. Having a Kerio Connect server along with A record mail.example.com requires you to create an MX record.
PTR records allow the DNS resolver to deliver an IP address and receive a reverse DNS lookup. Most strict mail servers perform a forward lookup on your mail server name, verify whether the IP address reads off the connection, and performs a PTR lookup on the IP address.
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