root@cba110:/etc/apt# apt-get install dovecot-imapd dovecot-pop3d
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  dovecot-imapd dovecot-pop3d
0 upgraded, 2 newly installed, 0 to remove and 2 not upgraded.
Need to get 364 kB/790 kB of archives.
After this operation, 1085 kB of additional disk space will be used.
Get:1 http://httpredir.debian.org/debian/ wheezy/main dovecot-pop3d amd64 1:2.1.7-7+deb7u1 [364 kB]
Fetched 364 kB in 0s (818 kB/s)       
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_ALL to default locale: No such file or directory
Selecting previously unselected package dovecot-imapd.
(Reading database ... 18793 files and directories currently installed.)
Unpacking dovecot-imapd (from .../dovecot-imapd_1%3a2.1.7-7+deb7u1_amd64.deb) ...
Selecting previously unselected package dovecot-pop3d.
Unpacking dovecot-pop3d (from .../dovecot-pop3d_1%3a2.1.7-7+deb7u1_amd64.deb) ...
Setting up dovecot-imapd (1:2.1.7-7+deb7u1) ...
locale: Cannot set LC_ALL to default locale: No such file or directory

Creating config file /etc/dovecot/conf.d/20-imap.conf with new version
cp: cannot create regular file `/etc/dovecot/conf.d/20-imap.conf': No such file or directory
dpkg: error processing dovecot-imapd (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up dovecot-pop3d (1:2.1.7-7+deb7u1) ...
locale: Cannot set LC_ALL to default locale: No such file or directory

Creating config file /etc/dovecot/conf.d/20-pop3.conf with new version
cp: cannot create regular file `/etc/dovecot/conf.d/20-pop3.conf': No such file or directory
dpkg: error processing dovecot-pop3d (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 dovecot-imapd
 dovecot-pop3d
E: Sub-process /usr/bin/dpkg returned an error code (1)