When configuring and composing the email messages for the "Sales Order Statuses" most things are fairly straight-forward and easy to understand.
 
I know how the "reply to" field works, and how it differs from the "from" field. However... I don't understand what the "return path" is for.
 
Does anyone know anything about this?

From another source:
Reply-To:
The address to which replies should be sent. Often absent from the message, and very easily forgeable. However, it often provides a clue. For example, forged spam often has a legitimate Reply-To: field so that the spammer can receive mail orders.
 
Return-Path:
The email address for return mail. Same as Reply-To:

If it's the same thing... why have both?

bump

Info about email headers here: http://en.wikipedia.org/wiki/Header_(E-Mail)
 
It is normal to have the option to define different addresses for "reply to" and "from" although in many cases the "reply to" is left empty or is the same as "from".
 
DickS