This article was originally published as part of the Pobox blog. Pobox was acquired by Fastmail in 2015.

When we at Pobox Customer Service get a question about a particular message, one of the first things we usually ask is, "Can you send us the full headers of the message?"  The full headers are a treasure trove of information, reflecting (nearly) everything that happened to the message from the time it was sent to the time you received it.

This week, we've rolled out a new Help section, How to Read Email Headers, to provide a map of sorts, so you can mine that treasure trove yourself.  From the very basic question of "What are email headers?" to the super-advanced problem debugging of how to use email headers to figure out why you're getting two copies of messages, there's information at every level.  Please check it out.  If you have other questions about email headers you'd like to see featured there, just let us know!