Mail Headers - 1 (Mail Conversation)

This is an example fetched from RFC 2822 : Internet Message Format to get a glimpse of the format of e-mails

--------------------------------------------------

Mail Conversation Headers

Have a close look at Message-ID and References fields also...

Scene 1 : John Sends a Mail to Mary

----
From: John Doe
To: Mary Smith
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>

This is a message just to say hello.
So, "Hello".
----

When sending replies, the Subject field is often retained, though prepended with "Re: "

Scene 2 : Mary Sends a Reply Mail to John, (Note : She has a different Reply-To Address)

----
From: Mary Smith
To: John Doe
Reply-To: "Mary Smith: Personal Account"
Subject: Re: Saying Hello
Date: Fri, 21 Nov 1997 10:01:10 -0600
Message-ID: <3456@example.net>
In-Reply-To: <1234@local.machine.example>
References: <1234@local.machine.example>

This is a reply to your hello.
----

Note the "Reply-To:" field in the above message. When John replies
to Mary's message above, the reply should go to the address in the
"Reply-To:" field instead of the address in the "From:" field.

Scene 2 : John Sends a Reply Mail to Mary @ her Reply-To Address

----
To: "Mary Smith: Personal Account"
From: John Doe
Subject: Re: Saying Hello
Date: Fri, 21 Nov 1997 11:00:00 -0600
Message-ID:
In-Reply-To: <3456@example.net>
References: <1234@local.machine.example> <3456@example.net>

This is a reply to your reply.
----

-------------------------------------------------------------