Lesson 3 of 3
The DNS records you need to know
2 min
A domain's DNS zone is a list of records. Each one answers a specific question.
The everyday records
A: maps a name to an IPv4 address, e.g.insidx.com → 10.0.0.5.AAAA: the same for an IPv6 address.CNAME: makes one name an alias of another, e.g.www → insidx.com. A name with a CNAME can't have other records.MX: tells the world which servers receive email for the domain, with a priority number (lower wins).TXT: free text, used mostly for verification and email security.NS: lists the nameservers that are authoritative for the zone.
Email security records
Three TXT-based records stop people sending email that pretends to be from your domain:
- SPF lists the servers allowed to send your mail:
v=spf1 include:_spf.example.com -all - DKIM publishes a public key so receivers can check a message's signature.
- DMARC tells receivers what to do when SPF or DKIM fail, and where to send reports.
Without SPF, DKIM and DMARC, your legitimate email is far more likely to land in spam.
Reading a record
insidx.com. 300 IN MX 10 mail.insidx.com.Name, TTL in seconds, class (almost always IN), type, then the value.