How to find the hidden headers.

Most software programs only show key headers within the email message. For example:


Sometimes, when troubleshooting email delivery problems, we need to see ALL the headers. In particular, the Received Headers will show a step-by-step route that the email took along it's delivery path.

How to view headers in Gmail

  • Open the email in question.
  • Click the 3 dot Menu on the right side to show more options.

Open the email in question in Gmail

  • Choose Show Original.


How to read Received Headers

When reviewing Received Headers, start at the bottom and work your way up to trace the delivery path.

Received: by with SMTP id p20csp685660yba;

       Wed, 17 Aug 2016 10:08:07 -0700 (PDT)

Received: from ( [])

       by with ESMTPS id 19si20265380qkm.106.2016.

       for <[email protected]>

       (version=TLS1_2 cipher=AES128-SHA bits=128/128);

       Wed, 17 Aug 2016 10:08:07 -0700 (PDT)

Received-SPF: pass ( domain of [email protected] designates as permitted sender) client-ip=;

Received: from ([]) by

ip-10-232-151-47.ec2.internal with esmtps (Exim 4.82 #2) id 1ba4GF-0001TH-6K;

Wed, 17 Aug 2016 17:04:15 +0000

Received: from root by with local (Exim 4.82 #2) id

1ba4G6-0007Mo-HG for [email protected]; Wed, 17 Aug 2016

17:04:06 +0000

Other headers with useful clues

Delivered-To, Return-Path, and Message-Id can contain helpful information.

For example, the Return Path domain should match the sender's domain. If it does not, it could be Spam.

Delivered-To: [email protected]

Return-Path: <[email protected]>