How can i find out if two emails are in fact from the same person?

What tricks are got up to in an effort to convince me the sender is NOT the same person?

many thanks

everything you need to know is in the message header. depending on your mail client it differs on how to get that information. Outlook is right click->message options cut and paste the contents of the internet headers box into something like

many thanks "Ammohunt"

I use Mozi;la Firefox. Is this what you mean by "mail client"?

PLease tell be how I can tell if two messages are REALLY from one person, even when the sender is trying to hide this fact.

Many thanks

Many thanks: I see it depends on IP and ISP (whatever they are)

In the example given in your reference we are told:-
Received: from source ([]) by ([]) with SMTP; Wed, 20 Aug 2003 21:40:05 CDT
From: <>

I am still very conofused!
How MANY IP and ISP do I "have"?
Over the years I have used (and still use)
Outlook Express, Outlook, Mozilla Firefox, GoogleChrome
and the (ISPs?) BT Internet,, and Googlemail and Gmail
on both dialup and broadband
on a series of different computers but the same BT landline
My portable uses the restaurant over the road by radio

So how many "identities" do I have?
How can I make it clear that this is the same esdel to all my contacts?
(And if I say "This is esdel" will they believe me!
What "private" info can I give without risk?)

Many thanks with your help with what turns out to be such a complex question!

nice concept but really i have no idea about it. if i will get solution then i will reply with proper solution.

TCP/IP stands for Transmission control protocol/Internet Protocol that’s what allows computers on the internet to talk to each other think of it as their postal address. Each server that handles mail should have a unique IP Address assigned typically by and ISP(Internet Service Provider) The IP address usually is associated with a name Using DNS(Domain Name System) The other piece of this that relates to what you are asking is SMTP This protocol is the commonly accepted method based on RFC Standards that control how email is transferred from one system to the other. If an email message is valid it will comply to the standards(in a perfect world alot of email doesn't) and contain the required blocks of information within the email message header using the letter analogy this would be the equivalent of the from and to address so my original post naturally centered around that hidden piece of every email message. it Should contain your email address as either the recipient or the sender depending on whether you are sending or recieving naturally. Here is a little better description