Microtel2:/etc/init.d# aptitude purge courier-imap
Reading Package Lists... Done
Building Dependency Tree
Reading extended state information
Initializing package states... Done
Reading task descriptions... Done
The following packages will be automatically REMOVED:
  courier-imap
The following packages have been kept back:
  adduser apt apt-utils aptitude bash bind9 bind9-host debianutils dnsutils
  gnupg initscripts libfam0c102 libisccc0 mc netbase nfs-common passwd
  pciutils pppoeconf python python-newt reportbug ssh sysvinit tasksel
  util-linux w3m whiptail
The following packages will be REMOVED:
  courier-imap
0 packages upgraded, 0 newly installed, 1 to remove and 28 not upgraded.
Need to get 0B of archives. After unpacking 1483kB will be freed.
Do you want to continue? [Y/n/?] y
Writing extended state information... Done
(Reading database ... 31070 files and directories currently installed.)
Removing courier-imap ...
/etc/init.d/courier-imap: line 134: Mail: command not found
invoke-rc.d: initscript courier-imap, action "stop" failed.
dpkg: error processing courier-imap (--purge):
 subprocess pre-removal script returned error exit status 127
/etc/init.d/courier-imap: line 134: Mail: command not found
invoke-rc.d: initscript courier-imap, action "start" failed.
dpkg: error while cleaning up:
 subprocess post-installation script returned error exit status 127
Errors were encountered while processing:
 courier-imap
E: Sub-process /usr/bin/dpkg returned an error code (1)
Ack!  Something bad happened while installing packages.  Trying to recover:
Reading Package Lists... Done
Building Dependency Tree
Reading extended state information
Initializing package states... Done
Reading task descriptions... Done