Are email headers different when email is in spam?

A bit of a particular question here

Let's say:

Jane emails Bill and her email ends up in spam
Then Jane emails Jebediah and her email does NOT end up in spam.

Assuming nothing changed in email setup and Jebediah got Jane's email because Jane was in his contacts:

Will the email headers in both instances look the same?

Our sysadmin team insists that they need emails from within the spam folder, but wouldn't they be identical in both cases if nothing changed on Jane's side.

Solution

While this is highly installation specific, some filtering packages do inject diagnostic headers into the email that indicates why the message was classified a particular way. These can be useful in identifying faults in delivery.

Google and Hotmail do this fairly reliably, though other services have different behaviour.

Remember, even if an email message was sent with identical headers to two different people the way the message was received can be dramatically different. The SMTP processing pipeline can be quite complicated and a number of processes can tap in, insert, remove, or otherwise manipulate headers before it ends up in the inbox.