$ sudo dpkg --force-all -P mailscanner
(Reading database ... 99211 files and directories currently installed.)
Removing mailscanner ...
Program MailScanner, 1 process(es), refused to die.
invoke-rc.d: initscript mailscanner, action "stop" failed.
dpkg: error processing mailscanner (--purge):
 subprocess pre-removal script returned error exit status 1
invoke-rc.d: initscript mailscanner, action "start" failed.
dpkg: error while cleaning up:
 subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
 mailscanner