broken pipe

Hi, habe auf meinem Ubuntu 8.04 LTS / Plesk 9.2.2 / Spamdyke MySQL 4.0.10 / SCP 2.03 folgendes Problem: Sep 15 19:18:51 www spamdyke[32570]: ERROR: unable to write 36 bytes to file descriptor 6: Broken pipe Sep 15 19:18:51 www spamdyke[32570]: FILTER_OTHER: response: "451 timeout...