Hi
No I try send mail from my web application I develop by Laravel 5.4
After Search How TO send Mail From LEMP Ubuntu 16.04 I followed This Tutorial
But When Try Install Postfllx this Message Comes to me on Putty

Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 mailutils : Depends: mailutils-common (= 1:2.99.99-1ubuntu2) but it is not going to be installed
             Depends: default-mta or
                      mail-transport-agent
             Depends: guile-2.0-libs but it is not going to be installed
             Depends: libmailutils4 (>= 1:2.99.99) but it is not going to be installed
 sendmail : Depends: sendmail-bin but it is not going to be installed
 sensible-mda : Depends: sendmail-bin but it is not going to be installed or
                         mail-transport-agent
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

How Can I fix this ??
Thank's