diff --git a/install_postfixadmin.sh b/install_postfixadmin.sh
index 703ee86..6f5ec0b 100755
--- a/install_postfixadmin.sh
+++ b/install_postfixadmin.sh
@@ -1726,6 +1726,8 @@ _failed=false
 > $log_file
 perl -i -n -p -e "s#^(\s*\\\$CONF\['transport_options'\]\s*=.*)#//\n//! \"transport_options\" will be overridden - see end of configfile\n//\n\1#" \
    $pfa_conf_file >> $log_file 2>&1 || _failed=true
+perl -i -n -p -e "s#^(\s*\\\$CONF\['transport_default'\]\s*=.*)#//\n//! \"transport_default\" will be overridden - see end of configfile\n//\n\1#" \
+   $pfa_conf_file >> $log_file 2>&1 || _failed=true
 
 cat <<EOF >> $pfa_conf_file 2> $log_file
 
@@ -1737,6 +1739,9 @@ cat <<EOF >> $pfa_conf_file 2> $log_file
    'local',    // for system accounts
    'relay'     // for backup mx
 );
+// Transport default
+// You should define default transport. It must be in array above.
+\$CONF['transport_default'] = 'lmtp:unix:private/dovecot-lmtp';
 EOF
 
 perl -i -n -p -e "s#^(\s*\\\$CONF\['vacation'\]\s*=.*)#//!\1\n\\\$CONF['vacation'] = 'YES';#" \