How-To
How to analyze an email header and find out why mail went to spam
In short: To analyze an email header: open the message, find 'Show original' or 'View source', copy the raw text, and paste it into a free Email Header Analyzer. It decodes the SPF, DKIM and DMARC results, the server hops and the timing, so you can see exactly why a message was filtered or delayed.
On this page
Step 1: Get the raw header
Each client exposes it differently:
- Gmail: open the message, click the three dots, choose Show original.
- Outlook: open the message, File > Properties, copy the Internet headers (or View message source in new Outlook).
- Apple Mail: View > Message > All Headers.
Copy the entire block, including every Received line.
Step 2: Analyze it
- Open the analyzer. Go to the free Inboxlogy Email Header Analyzer.
- Paste the raw header. Drop in the full text you copied.
- Click Analyze. The tool parses it in your browser.
- Read the results. It shows SPF, DKIM and DMARC verdicts, the hop-by-hop path and timestamps.
Step 3: Diagnose the problem
Match what you see to the fix:
- spf=fail: the sending server is not in your SPF record. Fix it with the SPF Generator.
- dkim=fail: the signature did not verify. Check your key with the DKIM Checker.
- dmarc=fail: neither SPF nor DKIM aligned. Review alignment and your DMARC setup.
- Big timing gaps: a slow hop, often greylisting. Usually resolves on retry.
Step 4: Confirm the fix
After making changes, send a fresh test and pull its header again. The authentication lines should now read pass across SPF, DKIM and DMARC. If they do, you have removed the authentication reasons a message would be filtered.
Find out why mail hit spam
Paste a raw header and get a plain-English read on authentication, routing and timing.
Open the Email Header Analyzer →All free toolsFrequently asked questions
How do I see the raw header in Gmail?
Open the message, click the three-dot menu, and choose Show original. That page shows the full raw header and the SPF, DKIM and DMARC summary you can copy into an analyzer.
What does spf=fail in a header mean?
The server that sent the message is not listed in the sending domain's SPF record. Add it with an SPF Generator, keeping under the 10-lookup limit, then re-test.
Why are there so many Received lines?
Each Received line is one server hop the message passed through, newest at the top. Reading them bottom to top traces the full path from sender to recipient.
Does the analyzer store my email?
No. The Email Header Analyzer parses the header locally in your browser. Nothing is uploaded or stored.