How do you verify email trail/path?

[Mascot]

Hi,

I just have a quick question. Is there any way to verify an email path or
trail? I only ask because I have a coworker who I requested something from
over a month ago and he never sent it to me so I have been bugging him about
getting it. He had claimed that he had already sent it to me but I looked
and could not find it. Anyway after doging my emails and phone calls he
finally forwarded it to me. However when I looked at the email it appears
as if he just typed in the info as if it was from a previous email and the
FW: in the subject line. So I want to know if there is anyway for me to
verify that this email actually was forwarded from previous emails.

let me know.

Thanks