First, you need to make sure that you’re eligible to vote absentee by mail! Tenn. Code Ann. § 2-6-201. Per the Secretary of State’s website, a registered voter may request an application for a by-mail ballot no earlier than ninety (90) days before the election and no later than seven (7) days before the election. To be processed for the next election, the application must be received by the election commission no later than seven (7) days before the election.