A DNS ‘text’ or TXT record allows a domain administrator to enter text into the Domain Name System. Although it was initially intended as a place for administrators to place human-readable notes, it’s now also possible to enter some machine-readable data into TXT records. In simple terms, it gives domain administrators the ability to provide text information to sources outside the domain and can be used for a variety of purposes.
Only text strings can go into the value field of a TXT record and the domain administrator can enter any text they want to associate with their domain. However, most DNS servers put a limit on how big TXT records can be and how many records they can store.
What are TXT Records Used For?
The most important uses for TXT records are spam prevention and domain ownership verification.
In respect of spam prevention, spam senders often try to fake the domains from which they send their email messages from. Here, TXT records are a key component of several email authentication methods that help to verify if a message is from a trusted source.
Although domain ownership verification was not initially a feature of TXT records, this approach has been adopted by some cloud providers and other webmaster tools. Here, by uploading a TXT record with specific information or editing a current TXT record to include the information, a domain administrator can prove that they control the domain. The tool or cloud provider can then check the TXT record and see that it has been changed as requested.
An analogy would be to compare it to the process of a user confirming their email address by opening and clicking a link sent to that email, and in the process proving they own the address.
Why are TXT Records Important?
Many cloud providers like Google, Office 365, and others require a special verification code via TXT records to be added into a specific domain’s DNS zone. In this way, the domain administrator can prove to these cloud providers that they are the actual owners of that particular domain.
It’s also important to configure TXT records correctly in respect of SPF records, DKIM records, DMARC records to ensure that it’s more difficult for spammers to fake a specific domain. As a result, when these records are properly configured, email deliverability will not be affected.