digen said:You mean to say which host was the email sent from?
You'll have to enable "Full email Headers" or a similar option under the settings/preferences of each account.
After enabling afaik its the X-Originating IP field which reveals the true IP of the sender.
EDIT:Here is a similar discussion> email headers
To view the time or date a message was sent, or to view the email address of the person who sent you a message, click 'More options' and then click 'Show original.' This displays the full header of a message.