root@vmi160223:~# apt-get remove postfix
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  apache2 apache2-bin apache2-data apache2-doc apache2-suexec-custom apache2-utils awstats bind9 bind9utils clamav clamav-base clamav-daemon clamav-docs clamav-freshclam clamav-testfiles clamdscan db-util db5.3-util
  default-mysql-client default-mysql-server dovecot-core dovecot-imapd dovecot-pop3d ebtables firewalld fontconfig-config fonts-dejavu-core fonts-lato galera-3 geoip-database gir1.2-glib-2.0 ipset jailkit javascript-common
  libapache2-mod-fcgid libapache2-mod-php libapache2-mod-php7.0 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libberkeleydb-perl libbind9-140 libcgi-fast-perl libcgi-pm-perl libclamav7 libconfig-inifiles-perl
  libcrypt-openssl-bignum-perl libcrypt-openssl-rsa-perl libdbus-glib-1-2 libdns162 libexttextcat-2.0-0 libexttextcat-data libfcgi-bin libfcgi-dev libfcgi-perl libfcgi0ldbl libfontconfig1 libgd3 libgeoip1 libgirepository-1.0-1
  libhtml-template-perl libio-multiplex-perl libipset3 libirs141 libisc160 libisccc140 libisccfg140 libjbig0 libjpeg62-turbo libjs-jquery libjson-c3 libllvm3.8 libltdl7 liblua5.2-0 liblwres141 libmail-dkim-perl libmail-spf-perl
  libmcrypt4 libmemcached11 libmemcachedutil2 libmspack0 libnet-cidr-perl libnet-dns-perl libnet-ip-perl libnet-rblclient-perl libnet-server-perl libnet-xwhois-perl libnetaddr-ip-perl libnl-3-200 libnl-genl-3-200 libparse-syslog-perl
  libruby2.3 libstemmer0d libtfm1 libtiff5 libtirpc1 libwebp6 libxpm4 libyaml-0-2 lsof mariadb-server-10.1 mariadb-server-core-10.1 mysql-client mysql-server ntpdate php-cgi php-fpm php-mcrypt php-mysql php7.0-cgi php7.0-fpm
  php7.0-mcrypt php7.0-mysql postfix-sqlite postgrey procmail procmail-wrapper proftpd-basic python3-dbus python3-decorator python3-gi python3-selinux python3-six python3-slip python3-slip-dbus quota rake re2c ri ruby ruby-did-you-mean
  ruby-minitest ruby-net-telnet ruby-power-assert ruby-test-unit ruby2.3 ruby2.3-doc rubygems-integration sa-compile sasl2-bin socat spamassassin spamc webalizer
Use 'apt autoremove' to remove them.
The following packages will be REMOVED:
  postfix postfix-pcre virtualmin-lamp-stack
0 upgraded, 0 newly installed, 3 to remove and 0 not upgraded.
After this operation, 4,443 kB disk space will be freed.
Do you want to continue? [Y/n] n