Sendmail error message – ‘general protection’

Recently I encounted this Sendmail problem:

Sendmail error: kernel: [617859.792404] sh[13556] general protection ip:b7794aa8 When trying to send an email.

For me – the solution was:

rm /dev/null

then recreate it:

mknod -m 0666 /dev/null c 1 3

I think I trashed my /dev/null recently and the above helped.