Spool file is locked (another process is handling this message)

While sending mail if you get the error



Spool file is locked (another process is handling this message)
Delivery attempt for Message ID 1EQoCE-00032w-3v

Message 1EQoCE-00032w-3v is locked
delivering 1EQoCE-00032w-3v
LOG: skip_delivery MAIN
Spool file is locked (another process is handling this message)

Solution
/scripts/courierup --force
/scripts/eximup --force