diff --git a/src/deb/vesta/postinst b/src/deb/vesta/postinst
index 0ac3a7c0f..f8452efb6 100755
--- a/src/deb/vesta/postinst
+++ b/src/deb/vesta/postinst
@@ -198,6 +198,15 @@ if [ ! -f "/usr/local/vesta/data/upgrades/limit_max_recipients" ]; then
     fi
 fi
 
+# Fixing Roundcube to send via authenticated SMTP user instead via php
+if [ ! -f "/usr/local/vesta/data/upgrades/roundcube_smtp_auth" ]; then
+    touch /usr/local/vesta/data/upgrades/roundcube_smtp_auth
+    if [ -f "/etc/roundcube/defaults.inc.php" ]; then
+        echo "=== Fixing Roundcube to send via authenticated SMTP user instead via php"
+        sed -i "s#^\$config\['smtp_user'\].*#\$config\['smtp_user'\] = '%u';#g" /etc/roundcube/defaults.inc.php
+        sed -i "s#^\$config\['smtp_pass'\].*#\$config\['smtp_pass'\] = '%p';#g" /etc/roundcube/defaults.inc.php
+    fi
+fi
 
 # Run custom triggers
 if [ -x "/root/vesta-patch.sh" ]; then