Jake Paul says his $50 MILLION fight offer to Conor McGregor is "real as f*ck" -- and he's got the "proof of funds" email from the bank to prove it.
Paul says he's backed by bona fide commercial real estate billionaires -- and he's got an email from a Senior VP at Signature Bank in NY which shows benefactor's money is legit and ready to be deployed.
The problem ... Jake says Conor has been radio silent since he made the fight offer.
"We're talking to his team," Paul said ... "[Conor] looked at my DM on Instagram.