A demand letter is a letter you can send to try to resolve a dispute before going to court. Demand letters are often sent in cases where someone owes money.Mail for released inmates is returned to sender or sent to the dead letter department at the US Post Office. Legal mail will be opened in the inmate's presence. Write a Formal Demand Letter in Dallas for requesting money, possession of assets, or action on a matter. Fill-out and send in form and supporting documentation establishing your right to receive the property. Send only a check, cashier's check, or money order made payable to the "City of Dallas" through the mail. Due to high volume and duplicate filings, we are no longer accepting filings via email or fax. Please file all filings and pleadings through eFileTexas. Use this online tool from Lone Star Legal Aid to file an answer in a debt collection lawsuit in Justice court.