Email Headers

Occasionally the investigation of a support topic on the FTH forums will require additional technical information from the email in question.

If you are requested to provide the 'email header' this means the FTH support team requires technical information that usually isn't visible in the normal inbox view of the email message.

1. Providing your email header to the FTH support team.

Copy the entirety of your email header to a text file (.txt) and attach it to a message in your forum topic for the issue.

Please continue reading for help understanding the location and purpose of email headers and why they are important for some FTH troubleshooting activities.

2. What is meant by the term "email headers"?

Header is information contained in the email that describes how it moved between the sender and recipient(s).

Additional terms relevant to this topic;

Server is a device designed to move email messages around the internet.

Client is the program or web page where you read and write emails.

Body is the content of the email.

3. What is contained in the email headers?

Typically a portion of the Header is visible in your inbox; From, To, CC, Subject...

The header also contains everything the sending and receiving servers must know in order to properly transfer the email between them. Language and font encoding, security protocol, server addresses, etc. Imagine how all this information multiples with the number of recipients.

4. Why can't you see email headers from your email inbox? 

Headers contain a substantial amount of information that isn't necessary for day-to-day reading and managing your emails.

5. How is what is in the email headers related to what you see in your email inbox? 

Each email message must contain all the information required to move it between sender and recipient email servers & clients. Email clients are designed to conceal all this information that isn't necessary for you to manage your email.

6. Why are email headers even used or needed?

Before an email leaves your outbox the sending and receiving email servers must communicate with each other and agree to transfer the message. The wealth of behind-the-scenes information contained in the header enables to the servers accomplish this.

7. Why do we ask for email headers?  Can't we just go by the information we already have in the email logs?

The formats and methods used by countless email servers and clients is practically unlimited. FTH email logs are limited to basic success/fail delivery information. The substantial amount of information in various formats contained in an email header can not reasonably be collected or retained.

If you are requested to provide the email header the FTH support team needs to study information found only in the header.

8.  How do you get the email headers for different email systems?

The way to find these email headers varies widely by system and email client.

You may see terms such as internet headers, message headers, raw email header, etc. Various similar terms refer to the same thing. Sometimes other terminology is used. For example, in Gmail it's called 'Show Original'.

You can do a web search for 'how to find email header for [the name of your email client]'. 

9. Suggested resources:

https://mxtoolbox.com/Public/Content/EmailHeaders/

https://www.mailjet.com/blog/deliverability/how-to-read-email-headers/