During an exchange, did you sell your Relinquished Property and later receive a Mortgage Escrow Overage Check from your previous Lender?
Lenders typically in most cases refund escrow funds directly to the borrower. They tend to never redirect the funds elsewhere. Having said that, these lender impound funds (escrow overage funds) are not sale proceeds from the sale of your relinquished property and should not go to the 1031 Exchange Qualified Intermediary. They are typically operating items such as (property taxes, insurance, etc.) and should go to you.