SPF record checker
SPF checker: read a domain’s SPF record, list its mechanisms e count the DNS lookups against the limit de 10.
Queries go a Cloudflare’s public DNS over HTTPS service when you press the button. Up a 15 queries are made a follow include records.
Sobre SPF record checker
SPF checker: read a domain’s SPF record, list its mechanisms e count the DNS lookups against the limit de 10.
Faz parte da secção «Dados e redes» do SmartCalcy. Funciona no seu navegador sem conta, usa a sua própria moeda e unidades (altere-as no topo da página) e dá estimativas apenas a título informativo, por isso consulte as orientações oficiais antes de confiar num resultado.
Como usar a SPF record checker
O que calcula e quando usar
Reads a domain’s SPF record, the list de servers allowed a send email por it, e checks it por common faults: more than one record, a missing “all” policy, e more than 10 DNS lookups, which makes SPF fail. It follows include records a count the lookups.
Como usar, passo a passo
- Enter the domain, por Exemplo Exemplo.com.
- Press “Check SPF”.
- Read the verdict e the number de DNS lookups used out de 10.
- Review the mechanisms list e qualquer warnings.
O que significa cada campo
- Domain Nome – The domain used em the sender’s address.
Como ler os resultados
- Verdict – Looks valid, ou Needs attention when a problem é found.
- Policy – What happens a mail from servers that are not listed: hard fail, soft fail, neutral ou allow.
- DNS lookups – Lookups needed by incluir, a, mx, ptr, exists e redirect terms, compared with the limit de 10.
- Mechanisms – Every Prazo em the record, with included records indented beneath their parent.
A fórmula
The record é the TXT value starting v=spf1. Each include, a, mx, ptr, exists ou redirect term costs one DNS lookup, e included records add their own. ip4 e ip6 terms e “all” cost none. The RFC limit é 10 lookups.
Um exemplo prático
v=spf1 incluir:_spf.Exemplo.net a mx -all uses three lookups por its own terms plus those inside the included record, e termina em -all, so unlisted servers are rejected.
Premissas e limites
- A most 15 queries are made while following includes, e nesting stops depois 5 levels.
- A domain may need a record only por mail it sends. Domains that send Não mail should publish v=spf1 -all.
- The check does not test whether a particular server would pass.
Erros comuns
- Publishing two SPF records. Only one é allowed, so merge them into one.
- Ending with +all, which lets anyone send as your domain.
- Adding every email service as an incluir e passing 10 lookups, which voltas SPF into a permanent error.
Perguntas frequentes
What é SPF?
Sender Policy Framework é a DNS record that lists the servers allowed a send email por a domain.
What é the difference between -all e ~all?
-all asks receivers a reject unlisted senders. ~all asks them a accept but mark the mail as suspicious.
Why é there a limit de 10 lookups?
It stops a record de forcing receivers into longa chains de DNS queries. Going excedido it makes SPF return a permanent error.
Is SPF enough a stop spoofing?
Não. Use it with DKIM e DMARC.
Does this tool send email?
Não. It only reads DNS records.