1) The letter should be addressed to the Board of Education (or Board of Directors if the school is private). Under the Texas Education Code, contract employees are required to resign no later than 45 days before the first day of instruction for the school year.Add contact details, company name, and date. I recently got hired in a new district and am extremely excited. Do I need to call my principal and department head to resign or is an email ok? Work in modern facilities, and use cutting-edge technology. I have had nothing but a positive experience working as an officer. Yes, mentioning personal reasons in a resignation letter is acceptable.