You're right that the headers will contain proper timestamps from the
servers along the way, but when a message is displayed, and the
headers that are used for reply (as in below) are all generated from
the sending computer.
You can demonstrate this yourself by just changing your local clock,
then clear your cache so your GMail is fresh, and send a message to
yourself only. It won't come into the Inbox, but when you look in
Sent Mail it will have the time your computer has on it.
--
Albert Einstein - "The release of atomic energy has not created a new
problem. It has merely made more urgent t...