diff --git a/nixos/modules/services/mail/postfix.nix b/nixos/modules/services/mail/postfix.nix
index 2b9175036be..ab6ad390600 100644
--- a/nixos/modules/services/mail/postfix.nix
+++ b/nixos/modules/services/mail/postfix.nix
@@ -9,14 +9,14 @@ let
   group = cfg.group;
   setgidGroup = cfg.setgidGroup;
 
+  haveAliases = cfg.postmasterAlias != "" || cfg.rootAlias != "" || cfg.extraAliases != "";
+  haveTransport = cfg.transport != "";
+  haveVirtual = cfg.virtual != "";
+
   mainCf =
     ''
       compatibility_level = 2
 
-      queue_directory = /var/postfix/queue
-      command_directory = ${pkgs.postfix}/sbin
-      daemon_directory = ${pkgs.postfix}/libexec/postfix
-
       mail_owner = ${user}
       default_privs = nobody
 
@@ -57,8 +57,6 @@ let
         else
           "[" + cfg.relayHost + "]"}
 
-      alias_maps = hash:/var/postfix/conf/aliases
-
       mail_spool_directory = /var/spool/mail/
 
       setgid_group = ${setgidGroup}
@@ -80,12 +78,15 @@ let
     + optionalString (cfg.recipientDelimiter != "") ''
       recipient_delimiter = ${cfg.recipientDelimiter}
     ''
-    + optionalString (cfg.virtual != "") ''
-      virtual_alias_maps = hash:/etc/postfix/virtual
+    + optionalString haveAliases ''
+      alias_maps = hash:/etc/postfix/aliases
     ''
-    + optionalString (cfg.transport != "") ''
+    + optionalString haveTransport ''
       transport_maps = hash:/etc/postfix/transport
     ''
+    + optionalString haveVirtual ''
+      virtual_alias_maps = hash:/etc/postfix/virtual
+    ''
     + cfg.extraConfig;
 
   masterCf = ''
@@ -158,6 +159,7 @@ in
     services.postfix = {
 
       enable = mkOption {
+        type = types.bool;
         default = false;
         description = "Whether to run the Postfix mail server.";
       };
@@ -168,21 +170,25 @@ in
       };
 
       setSendmail = mkOption {
+        type = types.bool;
         default = true;
         description = "Whether to set the system sendmail to postfix's.";
       };
 
       user = mkOption {
+        type = types.str;
         default = "postfix";
         description = "What to call the Postfix user (must be used only for postfix).";
       };
 
       group = mkOption {
+        type = types.str;
         default = "postfix";
         description = "What to call the Postfix group (must be used only for postfix).";
       };
 
       setgidGroup = mkOption {
+        type = types.str;
         default = "postdrop";
         description = "
           How to call postfix setgid group (for postdrop). Should
@@ -191,6 +197,7 @@ in
       };
 
       networks = mkOption {
+        type = types.nullOr (types.listOf types.str);
         default = null;
         example = ["192.168.0.1/24"];
         description = "
@@ -201,6 +208,7 @@ in
       };
 
       networksStyle = mkOption {
+        type = types.str;
         default = "";
         description = "
           Name of standard way of trusted network specification to use,
@@ -210,6 +218,7 @@ in
       };
 
       hostname = mkOption {
+        type = types.str;
         default = "";
         description ="
           Hostname to use. Leave blank to use just the hostname of machine.
@@ -218,6 +227,7 @@ in
       };
 
       domain = mkOption {
+        type = types.str;
         default = "";
         description ="
           Domain to use. Leave blank to use hostname minus first component.
@@ -225,6 +235,7 @@ in
       };
 
       origin = mkOption {
+        type = types.str;
         default = "";
         description ="
           Origin to use in outgoing e-mail. Leave blank to use hostname.
@@ -232,6 +243,7 @@ in
       };
 
       destination = mkOption {
+        type = types.nullOr (types.listOf types.str);
         default = null;
         example = ["localhost"];
         description = "
@@ -241,6 +253,7 @@ in
       };
 
       relayDomains = mkOption {
+        type = types.nullOr (types.listOf types.str);
         default = null;
         example = ["localdomain"];
         description = "
@@ -249,6 +262,7 @@ in
       };
 
       relayHost = mkOption {
+        type = types.str;
         default = "";
         description = "
           Mail relay for outbound mail.
@@ -256,6 +270,7 @@ in
       };
 
       lookupMX = mkOption {
+        type = types.bool;
         default = false;
         description = "
           Whether relay specified is just domain whose MX must be used.
@@ -263,11 +278,13 @@ in
       };
 
       postmasterAlias = mkOption {
+        type = types.str;
         default = "root";
         description = "Who should receive postmaster e-mail.";
       };
 
       rootAlias = mkOption {
+        type = types.str;
         default = "";
         description = "
           Who should receive root e-mail. Blank for no redirection.
@@ -275,6 +292,7 @@ in
       };
 
       extraAliases = mkOption {
+        type = types.lines;
         default = "";
         description = "
           Additional entries to put verbatim into aliases file, cf. man-page aliases(8).
@@ -282,6 +300,7 @@ in
       };
 
       extraConfig = mkOption {
+        type = types.str;
         default = "";
         description = "
           Extra lines to be added verbatim to the main.cf configuration file.
@@ -289,21 +308,25 @@ in
       };
 
       sslCert = mkOption {
+        type = types.str;
         default = "";
         description = "SSL certificate to use.";
       };
 
       sslCACert = mkOption {
+        type = types.str;
         default = "";
         description = "SSL certificate of CA.";
       };
 
       sslKey = mkOption {
+        type = types.str;
         default = "";
         description = "SSL key to use.";
       };
 
       recipientDelimiter = mkOption {
+        type = types.str;
         default = "";
         example = "+";
         description = "
@@ -312,6 +335,7 @@ in
       };
 
       virtual = mkOption {
+        type = types.lines;
         default = "";
         description = "
           Entries for the virtual alias map, cf. man-page virtual(8).
@@ -326,11 +350,24 @@ in
       };
 
       extraMasterConf = mkOption {
+        type = types.lines;
         default = "";
         example = "submission inet n - n - - smtpd";
         description = "Extra lines to append to the generated master.cf file.";
       };
 
+      aliasFiles = mkOption {
+        type = types.attrsOf types.path;
+        default = {};
+        description = "Aliases' tables to be compiled and placed into /var/lib/postfix/conf.";
+      };
+
+      mapFiles = mkOption {
+        type = types.attrsOf types.path;
+        default = {};
+        description = "Maps to be compiled and placed into /var/lib/postfix/conf.";
+      };
+
     };
 
   };
@@ -338,91 +375,104 @@ in
 
   ###### implementation
 
-  config = mkIf config.services.postfix.enable {
+  config = mkIf config.services.postfix.enable (mkMerge [
+    {
 
-    environment = {
-      etc = singleton
-        { source = "/var/postfix/conf";
-          target = "postfix";
-        };
+      environment = {
+        etc = singleton
+          { source = "/var/lib/postfix/conf";
+            target = "postfix";
+          };
 
-      # This makes comfortable for root to run 'postqueue' for example.
-      systemPackages = [ pkgs.postfix ];
-    };
-
-    services.mail.sendmailSetuidWrapper = mkIf config.services.postfix.setSendmail {
-      program = "sendmail";
-      source = "${pkgs.postfix}/bin/sendmail";
-      owner = "nobody";
-      group = "postdrop";
-      setuid = false;
-      setgid = true;
-    };
-
-    users.extraUsers = singleton
-      { name = user;
-        description = "Postfix mail server user";
-        uid = config.ids.uids.postfix;
-        group = group;
+        # This makes comfortable for root to run 'postqueue' for example.
+        systemPackages = [ pkgs.postfix ];
       };
 
-    users.extraGroups =
-      [ { name = group;
+      services.mail.sendmailSetuidWrapper = mkIf config.services.postfix.setSendmail {
+        program = "sendmail";
+        source = "${pkgs.postfix}/bin/sendmail";
+        group = setgidGroup;
+        setuid = false;
+        setgid = true;
+      };
+
+      users.extraUsers = optional (user == "postfix")
+        { name = "postfix";
+          description = "Postfix mail server user";
+          uid = config.ids.uids.postfix;
+          group = group;
+        };
+
+      users.extraGroups =
+        optional (group == "postfix")
+        { name = group;
           gid = config.ids.gids.postfix;
         }
+        ++ optional (setgidGroup == "postdrop")
         { name = setgidGroup;
           gid = config.ids.gids.postdrop;
-        }
-      ];
-
-    systemd.services.postfix =
-      { description = "Postfix mail server";
-
-        wantedBy = [ "multi-user.target" ];
-        after = [ "network.target" ];
-
-        serviceConfig = {
-          Type = "forking";
-          Restart = "always";
-          PIDFile = "/var/postfix/queue/pid/master.pid";
         };
 
-        preStart = ''
-          ${pkgs.coreutils}/bin/mkdir -p /var/spool/mail /var/postfix/conf /var/postfix/queue
+      systemd.services.postfix =
+        { description = "Postfix mail server";
 
-          ${pkgs.coreutils}/bin/chown -R ${user}:${group} /var/postfix
-          ${pkgs.coreutils}/bin/chown -R ${user}:${setgidGroup} /var/postfix/queue
-          ${pkgs.coreutils}/bin/chmod -R ug+rwX /var/postfix/queue
-          ${pkgs.coreutils}/bin/chown root:root /var/spool/mail
-          ${pkgs.coreutils}/bin/chmod a+rwxt /var/spool/mail
-          ${pkgs.coreutils}/bin/ln -sf /var/spool/mail /var/
+          wantedBy = [ "multi-user.target" ];
+          after = [ "network.target" ];
+          path = [ pkgs.postfix ];
 
-          ln -sf ${pkgs.postfix}/etc/postfix/postfix-files /var/postfix/conf
+          serviceConfig = {
+            Type = "forking";
+            Restart = "always";
+            PIDFile = "/var/lib/postfix/queue/pid/master.pid";
+            ExecStart = "${pkgs.postfix}/bin/postfix start";
+            ExecStop = "${pkgs.postfix}/bin/postfix stop";
+            ExecReload = "${pkgs.postfix}/bin/postfix reload";
+          };
 
-          ln -sf ${aliasesFile} /var/postfix/conf/aliases
-          ln -sf ${virtualFile} /var/postfix/conf/virtual
-          ln -sf ${mainCfFile} /var/postfix/conf/main.cf
-          ln -sf ${masterCfFile} /var/postfix/conf/master.cf
-          ln -sf ${transportFile} /var/postfix/conf/transport
+          preStart = ''
+            # Backwards compatibility
+            if [ ! -d /var/lib/postfix ] && [ -d /var/postfix ]; then
+              mkdir -p /var/lib
+              mv /var/postfix /var/lib/postfix
+            fi
+            mkdir -p /var/lib/postfix/data /var/lib/postfix/queue/{pid,public,maildrop}
 
-          ${pkgs.postfix}/sbin/postalias -c /var/postfix/conf /var/postfix/conf/aliases
-          ${pkgs.postfix}/sbin/postmap -c /var/postfix/conf /var/postfix/conf/virtual
-        '';
+            chown -R ${user}:${group} /var/lib/postfix
+            chown root /var/lib/postfix/queue
+            chown root /var/lib/postfix/queue/pid
+            chgrp -R ${setgidGroup} /var/lib/postfix/queue/{public,maildrop}
+            chmod 770 /var/lib/postfix/queue/{public,maildrop}
 
-        script = ''
-          ${pkgs.postfix}/sbin/postfix -c /var/postfix/conf start
-        '';
+            rm -rf /var/lib/postfix/conf
+            mkdir -p /var/lib/postfix/conf
+            ln -sf ${mainCfFile} /var/lib/postfix/conf/main.cf
+            ln -sf ${masterCfFile} /var/lib/postfix/conf/master.cf
+            ${concatStringsSep "\n" (mapAttrsToList (to: from: ''
+              ln -sf ${from} /var/lib/postfix/conf/${to}
+              postalias /var/lib/postfix/conf/${to}
+            '') cfg.aliasFiles)}
+            ${concatStringsSep "\n" (mapAttrsToList (to: from: ''
+              ln -sf ${from} /var/lib/postfix/conf/${to}
+              postmap /var/lib/postfix/conf/${to}
+            '') cfg.mapFiles)}
 
-        reload = ''
-          ${pkgs.postfix}/sbin/postfix -c /var/postfix/conf reload
-        '';
+            mkdir -p /var/spool/mail
+            chown root:root /var/spool/mail
+            chmod a+rwxt /var/spool/mail
+            ln -sf /var/spool/mail /var/
+          '';
+        };
+    }
 
-        preStop = ''
-          ${pkgs.postfix}/sbin/postfix -c /var/postfix/conf stop
-        '';
-
-      };
-
-  };
+    (mkIf haveAliases {
+      services.postfix.aliasFiles."aliases" = aliasesFile;
+    })
+    (mkIf haveTransport {
+      services.postfix.mapFiles."transport" = transportFile;
+    })
+    (mkIf haveVirtual {
+      services.postfix.mapFiles."virtual" = virtualFile;
+    })
+  ]);
 
 }
diff --git a/pkgs/servers/mail/postfix/3.0.nix b/pkgs/servers/mail/postfix/3.0.nix
index 8c625da2c9e..73ab8c8116f 100644
--- a/pkgs/servers/mail/postfix/3.0.nix
+++ b/pkgs/servers/mail/postfix/3.0.nix
@@ -1,8 +1,25 @@
-{ stdenv, fetchurl, makeWrapper, gnused, db, openssl, cyrus_sasl, coreutils
-, findutils, gnugrep, gawk, icu
+{ stdenv, lib, fetchurl, makeWrapper, gnused, db, openssl, cyrus_sasl
+, coreutils, findutils, gnugrep, gawk, icu, pcre
+, withPgSQL ? false, postgresql
+, withMySQL ? false, libmysql
+, withSQLite ? false, sqlite
 }:
 
-stdenv.mkDerivation rec {
+let
+  ccargs = lib.concatStringsSep " " ([
+    "-DUSE_TLS" "-DUSE_SASL_AUTH" "-DUSE_CYRUS_SASL" "-I${cyrus_sasl}/include/sasl"
+    "-DHAS_DB_BYPASS_MAKEDEFS_CHECK"
+    "-fPIE" "-fstack-protector-all" "--param" "ssp-buffer-size=4" "-O2" "-D_FORTIFY_SOURCE=2"
+   ] ++ lib.optional withPgSQL "-DHAS_PGSQL"
+     ++ lib.optionals withMySQL [ "-DHAS_MYSQL" "-I${libmysql}/include/mysql" ]
+     ++ lib.optional withSQLite "-DHAS_SQLITE");
+   auxlibs = lib.concatStringsSep " " ([
+     "-ldb" "-lnsl" "-lresolv" "-lsasl2" "-lcrypto" "-lssl" "-pie" "-Wl,-z,relro,-z,now"
+   ] ++ lib.optional withPgSQL "-lpq"
+     ++ lib.optional withMySQL "-lmysqlclient"
+     ++ lib.optional withSQLite "-lsqlite3");
+
+in stdenv.mkDerivation rec {
 
   name = "postfix-${version}";
 
@@ -13,35 +30,35 @@ stdenv.mkDerivation rec {
     sha256 = "00mc12k5p1zlrlqcf33vh5zizaqr5ai8q78dwv69smjh6kn4c7j0";
   };
 
-  buildInputs = [ makeWrapper gnused db openssl cyrus_sasl icu ];
+  buildInputs = [ makeWrapper gnused db openssl cyrus_sasl icu pcre ]
+                ++ lib.optional withPgSQL postgresql
+                ++ lib.optional withMySQL libmysql
+                ++ lib.optional withSQLite sqlite;
 
-  patches = [ ./postfix-script-shell.patch ];
+  patches = [ ./postfix-script-shell.patch ./postfix-3.0-no-warnings.patch ];
 
   preBuild = ''
     sed -e '/^PATH=/d' -i postfix-install
 
     export command_directory=$out/sbin
     export config_directory=/etc/postfix
+    export meta_directory=$out/etc/postfix
     export daemon_directory=$out/libexec/postfix
-    export data_directory=/var/lib/postfix
+    export data_directory=/var/lib/postfix/data
     export html_directory=$out/share/postfix/doc/html
     export mailq_path=$out/bin/mailq
     export manpage_directory=$out/share/man
     export newaliases_path=$out/bin/newaliases
-    export queue_directory=/var/spool/postfix
+    export queue_directory=/var/lib/postfix/queue
     export readme_directory=$out/share/postfix/doc
     export sendmail_path=$out/bin/sendmail
 
-    make makefiles \
-      CCARGS='-DUSE_TLS -DUSE_SASL_AUTH -DUSE_CYRUS_SASL -I${cyrus_sasl}/include/sasl \
-              -DHAS_DB_BYPASS_MAKEDEFS_CHECK \
-              -fPIE -fstack-protector-all --param ssp-buffer-size=4 -O2 -D_FORTIFY_SOURCE=2' \
-      AUXLIBS='-ldb -lnsl -lresolv -lsasl2 -lcrypto -lssl -pie -Wl,-z,relro,-z,now'
+    make makefiles CCARGS='${ccargs}' AUXLIBS='${auxlibs}'
   '';
 
   installTargets = [ "non-interactive-package" ];
 
-  installFlags = [ " install_root=installdir " ];
+  installFlags = [ "install_root=installdir" ];
 
   postInstall = ''
     mkdir -p $out
@@ -57,9 +74,9 @@ stdenv.mkDerivation rec {
   meta = {
     homepage = "http://www.postfix.org/";
     description = "A fast, easy to administer, and secure mail server";
-    license = stdenv.lib.licenses.bsdOriginal;
-    platforms = stdenv.lib.platforms.linux;
-    maintainers = [ stdenv.lib.maintainers.rickynils ];
+    license = lib.licenses.bsdOriginal;
+    platforms = lib.platforms.linux;
+    maintainers = [ lib.maintainers.rickynils ];
   };
 
 }
diff --git a/pkgs/servers/mail/postfix/postfix-3.0-no-warnings.patch b/pkgs/servers/mail/postfix/postfix-3.0-no-warnings.patch
new file mode 100644
index 00000000000..d93eaf0aaa0
--- /dev/null
+++ b/pkgs/servers/mail/postfix/postfix-3.0-no-warnings.patch
@@ -0,0 +1,86 @@
+diff -ru3 postfix-3.0.3/conf/postfix-script postfix-3.0.3-new/conf/postfix-script
+--- postfix-3.0.3/conf/postfix-script	2014-06-27 18:05:15.000000000 +0400
++++ postfix-3.0.3-new/conf/postfix-script	2016-01-09 17:51:38.545733631 +0300
+@@ -84,24 +84,6 @@
+ 	exit 1
+ }
+ 
+-# If this is a secondary instance, don't touch shared files.
+-
+-instances=`test ! -f $def_config_directory/main.cf ||
+-    $command_directory/postconf -c $def_config_directory \
+-    -h multi_instance_directories | sed 's/,/ /'` || {
+-	$FATAL cannot execute $command_directory/postconf!
+-	exit 1
+-}
+-
+-check_shared_files=1
+-for name in $instances
+-do
+-    case "$name" in
+-    "$def_config_directory") ;;
+-    "$config_directory") check_shared_files=; break;;
+-    esac
+-done
+-
+ #
+ # Parse JCL
+ #
+@@ -262,22 +244,6 @@
+ 	    -prune \( -perm -020 -o -perm -002 \) \
+ 	    -exec $WARN group or other writable: {} \;
+ 
+-	# Check Postfix root-owned directory tree owner/permissions.
+-
+-	todo="$config_directory/."
+-	test -n "$check_shared_files" && {
+-		todo="$daemon_directory/. $meta_directory/. $todo"
+-		test "$shlib_directory" = "no" || 
+-		    todo="$shlib_directory/. $todo"
+-	}
+-	todo=`echo "$todo" | tr ' ' '\12' | sort -u`
+-
+-	find $todo ! -user root \
+-	    -exec $WARN not owned by root: {} \;
+-
+-	find $todo \( -perm -020 -o -perm -002 \) \
+-	    -exec $WARN group or other writable: {} \;
+-
+ 	# Check Postfix mail_owner-owned directory tree owner/permissions.
+ 
+ 	find $data_directory/. ! -user $mail_owner \
+@@ -302,18 +268,11 @@
+ 	# Check Postfix setgid_group-owned directory and file group/permissions.
+ 
+ 	todo="$queue_directory/public $queue_directory/maildrop"
+-	test -n "$check_shared_files" && 
+-	   todo="$command_directory/postqueue $command_directory/postdrop $todo"
+ 
+ 	find $todo \
+ 	    -prune ! -group $setgid_group \
+ 	    -exec $WARN not owned by group $setgid_group: {} \;
+ 
+-	test -n "$check_shared_files" &&
+-	find $command_directory/postqueue $command_directory/postdrop \
+-	    -prune ! -perm -02111 \
+-	    -exec $WARN not set-gid or not owner+group+world executable: {} \;
+-
+ 	# Check non-Postfix root-owned directory tree owner/content.
+ 
+ 	for dir in bin etc lib sbin usr
+@@ -334,15 +293,6 @@
+ 
+ 	find corrupt -type f -exec $WARN damaged message: {} \;
+ 
+-	# Check for non-Postfix MTA remnants.
+-
+-	test -n "$check_shared_files" -a -f /usr/sbin/sendmail -a \
+-		-f /usr/lib/sendmail && {
+-	    cmp -s /usr/sbin/sendmail /usr/lib/sendmail || {
+-		$WARN /usr/lib/sendmail and /usr/sbin/sendmail differ
+-		$WARN Replace one by a symbolic link to the other
+-	    }
+-	}
+ 	exit 0
+ 	;;
+