Removing dovecot-managesieved
-----------------------------

If you remove (i.e. with dpkg -r or aptitude remove) this package you will
get an error something like this:

doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf: 
service(managesieve-login): executable is empty

To avoid it, make sure 
/etc/dovecot/conf.d/etc/dovecot/conf.d/20-managesieve.conf has been deleted, 
moved or completely commented out first.  Alternatively, purge the package 
instead of removing it.

If you do not do this, dovecot-core will be left in an unconfigured state 
because the error will cause a trigger to fail.  To fix this simply reinstall 
dovecot-core.