Question : Track emails without header information

Is there a way to trace the origin of an email wothout the header information?  One of my clients fired an employee and the person sent a nasty email to one of his clients in retaliation.  All my client has is a copy of the email that his client forwarded to him, not the original.  It wa sent from a Yahoo email account.  Any help would be greatly appreciated!

Answer : Track emails without header information

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