Plesk qmail returns the following error: “Deferred: 451 qmail-spp failure: plugins/chkrcptto: child crashed (#4.3.0)” This is caused by incorrect permissions on or a missinf /dev/null device. Remove any existing /dev/null and create a new one with the following commands. [text]~# mknod -m 666 /dev/full c 1 7 ~# chown root:root /dev/full[/text]