diff --git a/modoboa_installer/database.py b/modoboa_installer/database.py
index 291c119..d19d8d7 100644
--- a/modoboa_installer/database.py
+++ b/modoboa_installer/database.py
@@ -153,7 +153,7 @@ class MySQL(Database):
 
     default_port = 3306
     packages = {
-        "deb": ["mariadb-server", "libmysqlclient-dev"],
+        "deb": ["mariadb-server"],
         "rpm": ["mariadb", "mariadb-devel", "mariadb-server"],
     }
     service = "mariadb"
diff --git a/modoboa_installer/scripts/files/postfix/main.cf.tpl b/modoboa_installer/scripts/files/postfix/main.cf.tpl
index 0123e60..9bc9b44 100644
--- a/modoboa_installer/scripts/files/postfix/main.cf.tpl
+++ b/modoboa_installer/scripts/files/postfix/main.cf.tpl
@@ -142,10 +142,10 @@ postscreen_blacklist_action = enforce
 
 # Use some DNSBL
 postscreen_dnsbl_sites = 
-	zen.spamhaus.org*3
-	bl.spameatingmonkey.net*2
-	bl.spamcop.net
-	dnsbl.sorbs.net
+	zen.spamhaus.org=127.0.0.[2..11]*3
+	bl.spameatingmonkey.net=127.0.0.2*2
+	bl.spamcop.net=127.0.0.2
+	dnsbl.sorbs.net=127.0.0.[2..15]
 postscreen_dnsbl_threshold = 3 
 postscreen_dnsbl_action = enforce