Problem installing perfect server ubuntu on 16.04

I am following this guide:
The Perfect Server - Ubuntu 16.04 (Nginx, MySQL, PHP, Postfix, BIND, Dovecot, Pure-FTPD and ISPConfig 3.1)
I am trying to install ISPCONFIG and stuck at the first instance. That is while running the command

Code:

apt-get -y install postfix postfix-mysql postfix-doc mysql-client mysql-server openssl getmail4 rkhunter binutils dovecot-imapd dovecot-pop3d dovecot-mysql dovecot-sieve dovecot-lmtpd sudo

The following packages have unmet dependencies:
dovecot-lmtpd : Depends: dovecot-core (= 1:2.2.22-1ubuntu2) but 1:2.2.22-1ubuntu2.2 is to be installed
dovecot-mysql : Depends: dovecot-core (= 1:2.2.22-1ubuntu2) but 1:2.2.22-1ubuntu2.2 is to be installed

Need help how I can resolve this.

 

ok resolved. It's my mistake. actually left out an update repository from the instructions.