I'm seeing email backing up to earthlink.net with "451 System is temporarily unavailable", starting at 7:16 pm Central. They have four equally-weighted MX records. Two of them mx1 and mx4 are timing out (209.86.93.226 and 209.86.93.229) and mx2 experiences a "connection refused" (209.86.93.227). mx3 (209.86.93.228) does connect. Frank