# apt-get -f install ldap-utils
Reading package lists... Done
Building dependency tree... Done
ldap-utils is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
Need to get 0B of archives.
After unpacking 0B of additional disk space will be used.
Setting up dovecot-imapd (1.0.rc15-2) ...
Starting mail server: dovecotError: Can't use mail executable /usr/lib/dovecot/pop3: No such file or directory
invoke-rc.d: initscript dovecot, action "start" failed.
dpkg: error processing dovecot-imapd (--configure):
subprocess post-installation script returned error exit status 89
Errors were encountered while processing:
dovecot-imapd
E: Sub-process /usr/bin/dpkg returned an error code (1)


How I resolve ?

Means ldap-utils is already installed. What are you trying to accomplish by re-installing it?

You need dovecot-pop3d installed for the missing file you may have to remove the dovecot-imapd first before being able to install it.