What is a DNS TXT record?
Most DNS records contain data in a computer-readable language, but TXT records allow for both human- and computer-readable instructions. TXT records serve a variety of purposes, including domain ownership verification, email spam prevention and framework policies. They also provide general information and points of contact for the domain.
TXT records have no specific formatting requirements, but they’re not meant for large amounts of data. Values longer than 255 characters will need to be split into multiple parts, with each section that contains more than 255 characters enclosed in double quotes. In this case, both values would then need to be added to the TXT record.
How do TXT records prevent email spam?
TXT records act as an email authenticator by establishing that an email comes from a trusted source and includes all servers authorized to send messages on a domain’s behalf. They can also hold public key information (PKI) and store policies like Domain-based Message Authentication and Reporting & Conformance (DMARC).
What are DKIM records?
DKIM stands for Domain Keys Identified Mail. This type of record is a modified TXT record. DKIM records host public keys attached to specific domains, and they’re used to sign emails digitally. These records act as a security measure, helping to ensure emails aren’t altered during transit.
What are DMARC records?
DMARC stands for Domain-based Message Authentication, Reporting and Conformance. These records are another type of DNS TXT record. Their purpose is to signal to servers whether to quarantine, reject or allow a message to be delivered. DMARC records are also used to send reports to specified email addresses.
What is domain ownership verification?
Uploading or editing a TXT record to include important details about your domain serves to prove that you control the domain, enabling providers to validate the domain’s ownership. TXT records that are configured for domain ownership verification allow providers requiring verification to query your server and receive confirmation of ownership. An alternative is to add a TXT file that includes a verification string to your web server’s root directory.
What’s the difference between a TXT record and an SPF record?
SPF stands for Sender Policy Framework. SPFs were designed to verify which IP addresses or fully qualified domain names (FDQNs) are permitted to send mail for a specified domain, but SPF records have now been deprecated. Some providers still support SPF records, but TXT records are highly favored. Because an SPF record is a type of TXT record and all the same information can be stored in a TXT record, SPFs are redundant, and it’s recommended that TXT be used instead.
What is a TXT record lookup?
A DNS lookup tool can be used to test changes to TXT records to ensure the changes have been propagated. DNS lookup tools can also verify that a domain’s DKIM record is being returned properly.