SPF (Sender Policy Framework)

SPF (Sender Policy Framework, RFC 7208) is an email authentication method. The domain owner publishes a TXT record listing the IP addresses and services allowed to send mail for the domain, and receiving servers check the connecting IP against it.

Why it matters

Without SPF, anyone can send mail that claims to be from your domain. Receivers also weigh SPF results when deciding between inbox and spam. SPF checks the envelope sender (Return-Path), not the visible From address, so on its own it does not stop display-name spoofing; DMARC ties the two together.

Example

example.com.  3600 IN TXT "v=spf1 ip4:203.0.113.10 include:_spf.google.com ~all"

Mechanisms are checked left to right. ~all is a softfail for anything else; -all is a hard fail. Check with dig +short example.com TXT.

Common mistakes

• Publishing more than one v=spf1 record. Receivers treat that as a permanent error; merge them.
• Exceeding the limit of 10 DNS-querying mechanisms (include, a, mx, ptr, exists, redirect), which also returns a permanent error.
• Ending with +all or ?all, which authorizes everyone or nobody in particular.
• Forgetting a sender, such as a newsletter or invoicing tool, so its legitimate mail fails.

Related

• DKIM
• DMARC
• TXT record
• गाइड: Fix SPF too many DNS lookups
• टूल: SPF record checker

यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.