HOUSTON, TEXAS - September, 2004 - Enterprise Systems Corporation announced today that a Nortel Networks CallPilot solution has been selected for expansion of voice messaging at the main Harris County Appraisal District (HCAD) Campus in Houston. The existing Meridian Mail system channels were becoming overloaded due a tremendous taxpayer response this fall. The CallPilot system was chosen over a standard Meridian Mail expansion due to the Unified Messaging capabilities. HCAD was able to take advantage of an aggressive Meridian Mail to CallPilot migration program offered by Nortel Networks. of the Nortel Networks Meridian 1.