Let’s explore one DNS record with multiple purposes – the DNS TXT record. It is used for various verification methods, and it is essential to the right mail server functionality.
What is a DNS TXT record?
The DNS TXT record is one DNS record type with multiple purposes like authentication, verification, mail policies, and more. The DNS TXT record is showing domain information to external sources.
The TXT record has a text field that can be filled with readable instructions for people or with instructions for computers like cryptographic keys and email instructions.
You can add multiple TXT records for the same DNS zone. They can have different purposes, and sometimes they can work together, like in the case of DMARC.
Why do you need to use a DNS TXT record?
There are several reasons why you need to use DNS TXT records, and you can see the top reasons here:
Domain ownership verification. Some cloud providers like Google, Zendesk, and others want you to put a TXT record into your Master zone for the domain, so you can prove to them that you own it. They will provide you content for the record that you need to upload. Only the zone administrator will be able to add DNS records like the DNS TXT records.
Applying the Sender Policy Framework (SPF).
Email’s sender verification with DomainKeys Identified Mail (DKIM). The DKIM is a way that the domain owner can sign the emails that are sent on behalf of that domain name. The emails will be cryptographically protected, and the receiver will be able to verify the origin of the email. DKIM greatly lowers the risk of forged emails.
Zero-configuration networking DNS-based service discovery. The clients would be able to resolve services to hostnames with standard DNS queries. Each service has an SRV DNS record and TXT DNS record. The TXT contains the service-specific configuration.
Set Domain-based Message Authentication, Reporting, and Conformance (DMARC) policies for your domain name. The DMARC is used so to extra verify the sender by combining the SPF and DKIM in one last checking. You can put parameters to fail if one of the two fails or both, or non. It can guarantee to the receiver of the emails that the email wasn’t spoofed on the way and is coming from the right source (domain name). It also includes commands for the receiver, what to do in case of receiving fake emails pretending to be coming from a domain name. This feedback makes it a great tool for finding cybercriminals abusing with a domain name.
Simple text instructions for humans. You can add a TXT record with information about who is responsible for a zone or a service, extra data about the host, etc., and leave their contact. TXT record can have a text orientated for human eyes too.
The DNS TXT record is a must-have if you have a mail server and want to send, receive and see feedback for your emails. It can lower the spam, proof you own a domain name, sign messages, and more. It is a truly versatile DNS record that you need to master.