I’m an American retiree in Costa Rica. How to prove an email was falsified.

I'm an American retiree living in Costa Rica. I have a lawsuit vs. a corrupt attorney down here who has a hacker buddy who among other skills is able to falsify emails to make any email appear legitimate.  How can I show the "Costa Rica Bar Association" (who is arbitrating this case/this disagreement) that the emails submitted as paper documents in the "expediente" document for the casehave been falsified.  The whole batch have been created or altered and presented as though I sent them when I did not.  HELP!  Does Microsoft verify emails as legitimate for a fee? Thanks in advance, Jeff Lasher (*** Email address is removed for privacy ***) or best email address to use: (*** Email address is removed for privacy ***).