Sometimes I receive an email in my Gmail program that I would like to save in a folder but the subject line of my incoming email does not reflect the specific content of the email. For example, the email I receive might simply say "Daily Events"; before I move it to a folder to save, I would like to edit the subject to say "Daily Events 10/1 -- 10/10, 2013" so I can easily find that particular email again. I can do this with my Mindspring/Earthlink email program but not Gmail. Your help would be greatly appreciated!
The only way you could achieve this is by forwarding it to yourself and changing the subject of the forwarded email. There is no way you can change the subject (or any other detail for that matter) of an incoming email in Gmail.