TXT 记录
Stores arbitrary text — most often SPF, DKIM, DMARC and ownership-verification tokens.
TXT 记录是什么？
A TXT record holds free-form ASCII strings. In practice it is the home of email-authentication policy (SPF, DKIM, DMARC), ownership-verification tokens (Google, Microsoft, AWS, Let's Encrypt DNS-01) and a handful of niche protocols.
区域文件示例
example.com. 300 IN TXT "v=spf1 include:_spf.google.com -all" _dmarc.example.com. 300 IN TXT "v=DMARC1; p=reject; rua=mailto:dmarc@example.com"
常见用例
- ▸SPF: declare which servers are allowed to send mail "from" your domain.
- ▸DKIM: publish the public key used to sign your outbound mail.
- ▸DMARC: tell receivers what to do when SPF/DKIM fail (none / quarantine / reject) + where to send reports.
- ▸Domain verification: prove control of the domain to a cloud or SaaS provider.
常见坑
A TXT value is broken into 255-character chunks at the wire level — long DKIM keys are stored as multiple quoted strings. Most DNS UIs hide this, but some scripts can mis-concatenate.