Test Environment for Mailers (TEM) PostalOne! Release 31.0 will deploy to the Test Environment for Mailers (TEM) on Monday, June 11, 2012. PostalOne! TEM will be unavailable from 4:00 a.m. through 4:00 p.m. CDT. If you have any additional questions please contact the Help Desk at 800-522-9085.