Definition
The Received-SPF header is a header field that a receiving mail server adds to a message to record the result of the SPF check it performed. It shows the sender's IP address, the SPF result, and the domain that was evaluated. Deliverability specialists read this header to diagnose authentication problems and confirm whether a message passed or failed SPF at a given hop.
How It Works
When a server receives a message and performs an SPF check, it can append a header that documents the outcome. The header contains fields such as:
- The result, expressed as
pass,fail,softfail,neutral,none, orpermerror. - The sending IP address and the identity that was checked.
- The receiving server that performed the check.
A typical header looks like:
Received-SPF: pass (google.com: domain of sender@example.com designates 192.0.2.10 as permitted sender) client-ip=192.0.2.10;
The header is informational and, unlike the SPF check itself, is not directly used for filtering decisions. It is retained so that later recipients, postmasters, and forensic tools can understand what happened.
Why It Matters
The Received-SPF header is a primary diagnostic tool. When a sender's mail is being filtered, the header reveals exactly which SPF result the receiving server saw, and whether the problem is a fail, a softfail, or a none result from a missing record.
It is also useful for understanding forwarded mail. A message that passes SPF at the origin may show a fail or neutral result in a later Received-SPF header after forwarding, which helps distinguish genuine failures from forwarding artefacts.
Note that the Received-SPF header reflects SPF only. It does not show DKIM or DMARC results, which appear in separate headers such as Authentication-Results. For a complete picture, both headers should be examined together.
Example
A sender investigating spam-folder placement inspects the message headers and finds Received-SPF: fail with the sending IP. The sender realises its new sending IP was not added to the SPF record, updates the record, and subsequent messages show pass and reach the inbox.
Was this useful?
Related Glossary Terms
Abuse Complaint
An abuse complaint is a report from a recipient who marks an email as spam, which negatively affects sender reputation and deliverability.
Alt Text
Alt text is the written alternative to an image in an email, displayed when images are blocked, slow to load, or consumed by screen readers.
AOL Mail for Email Marketers
AOL Mail is a legacy email provider with specific deliverability requirements and rendering quirks, now operating as part of the Yahoo+AOL network under shared infrastructure.
Email Authentication Protocols
Email authentication protocols are technical standards that verify the identity of an email sender, helping mailbox providers distinguish legitimate mail from spam and phishing.
BIMI
BIMI (Brand Indicators for Message Identification) is an email standard that allows brands to display their logo next to their emails in supported email clients. It requires DMARC enforcement at quarantine or reject policy.
Bounce Management
Bounce management is the process of handling emails that are rejected by mailbox providers, including classification, removal of bad addresses and protection of sender reputation.
Frequently Asked Questions
Not typically. The header records the result of the SPF check that was already performed; the filtering decision is based on the check itself. The header exists for transparency and diagnosis.
Received-SPF documents only the SPF outcome at a single hop, while the Authentication-Results header aggregates SPF, DKIM, and DMARC results. Both are useful, and together they give a complete authentication picture.
A `neutral` result means the record used `?all`, while `none` means no SPF record was found for the evaluated domain. Both indicate the sender made no strong authorisation assertion for that IP.
Yes. Forwarding often changes the return path so that the forwarding server, not the original sender, performs the final SPF check. A fail in that context does not necessarily mean the original sender was at fault.