diff --git a/manifest.json b/manifest.json
index 97e5ab0..e9c4ceb 100644
--- a/manifest.json
+++ b/manifest.json
@@ -6,7 +6,7 @@
         "en": "Simple, modern, lightweight & fast web-based email client",
         "fr": "Client de messagerie Web simple, moderne, léger et rapide"
     },
-    "version": "2.15.3~ynh1",
+    "version": "2.15.3~ynh2",
     "url": "https://snappymail.eu/",
     "upstream": {
         "license": "AGPL-3.0-only",
diff --git a/scripts/config b/scripts/config
index b9e79f8..8a9110c 100644
--- a/scripts/config
+++ b/scripts/config
@@ -1,12 +1,4 @@
 #!/bin/bash
-# In simple cases, you don't need a config script. 
-
-# With a simple config_panel.toml, you can write in the app settings, in the 
-# upstream config file or replace complete files (logo ...) and restart services.
-
-# The config scripts allows you to go further, to handle specific cases 
-# (validation of several interdependent fields, specific getter/setter for a value,
-# display dynamic informations or choices, pre-loading of config type .cube... ).
 
 #=================================================
 # GENERIC STARTING
@@ -14,6 +6,7 @@
 # IMPORT GENERIC HELPERS
 #=================================================
 
+source _common.sh
 source /usr/share/yunohost/helpers
 
 ynh_abort_if_errors
@@ -22,81 +15,81 @@ ynh_abort_if_errors
 # RETRIEVE ARGUMENTS
 #=================================================
 
-final_path=$(ynh_app_setting_get $app final_path)
+phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
+current_fpm_footprint=$(ynh_app_setting_get --app=$app --key=fpm_footprint)
 
 #=================================================
 # SPECIFIC GETTERS FOR TOML SHORT KEY
 #=================================================
 
-get__amount() {
-    # Here we can imagine to have an API call to stripe to know the amount of donation during a month
-    local amount = 200
-
-    # It's possible to change some properties of the question by overriding it:
-    if [ $amount -gt 100 ]
+get__fpm_footprint() {
+    # Free footprint value for php-fpm
+    # Check if current_fpm_footprint is an integer
+    if [ "$current_fpm_footprint" -eq "$current_fpm_footprint" ] 2> /dev/null
     then
-    cat << EOF
-style: success
-value: $amount
-ask:
-  en: A lot of donation this month: **$amount €**
-EOF
+        echo "specific"
     else
-    cat << EOF
-style: danger
-value: $amount
-ask:
-  en: Not so much donation this month: $amount €
-EOF
+        echo "$current_fpm_footprint"
     fi
 }
 
-get__prices() {
-    local prices = "$(grep "DONATION\['" "$final_path/settings.py" | sed -r "s@^DONATION\['([^']*)'\]\['([^']*)'\] = '([^']*)'@\1/\2/\3@g" | sed -z 's/\n/,/g;s/,$/\n/')"
-    if [ "$prices" == "," ];
+get__free_footprint() {
+    # Free footprint value for php-fpm
+    # Check if current_fpm_footprint is an integer
+    if [ "$current_fpm_footprint" -eq "$current_fpm_footprint" ] 2> /dev/null
     then
-        # Return YNH_NULL if you prefer to not return a value at all.
-        echo YNH_NULL
+        # If current_fpm_footprint is an integer, that's a numeric value for the footprint
+        echo "$current_fpm_footprint"
     else
-        echo $prices
+        echo "0"
     fi
 }
 
-
-#=================================================
-# SPECIFIC VALIDATORS FOR TOML SHORT KEYS
-#=================================================
-validate__publishable_key() {
-
-    # We can imagine here we test if the key is really a publisheable key
-    (is_secret_key $publishable_key) &&
-        echo 'This key seems to be a secret key'
-}
-
 #=================================================
 # SPECIFIC SETTERS FOR TOML SHORT KEYS
 #=================================================
-set__prices() {
 
-    #---------------------------------------------
-    # IMPORTANT: setter are trigger only if a change is detected
-    #---------------------------------------------
-    for price in $(echo $prices | sed "s/,/ /"); do
-        frequency=$(echo $price | cut -d/ -f1)
-        currency=$(echo $price | cut -d/ -f2)
-        price_id=$(echo $price | cut -d/ -f3)
-        sed "d/DONATION\['$frequency'\]\['$currency'\]" "$final_path/settings.py"
+set__fpm_footprint() {
+    if [ "$fpm_footprint" != "specific" ]
+    then
+        ynh_app_setting_set --app=$app --key=fpm_footprint --value="$fpm_footprint"
+    fi
+}
 
-        echo "DONATION['$frequency']['$currency'] = '$price_id'" >> "$final_path/settings.py"
-    done
-    
-    #---------------------------------------------
-    # IMPORTANT: to be able to upgrade properly, you have to saved the value in settings too
-    #---------------------------------------------
-    ynh_app_setting_set $app prices $prices
+set__free_footprint() {
+    if [ "$fpm_footprint" == "specific" ]
+    then
+        ynh_app_setting_set --app=$app --key=fpm_footprint --value="$free_footprint"
+    fi
 }
 
 #=================================================
 # GENERIC FINALIZATION
 #=================================================
+
+ynh_app_config_validate() {
+    _ynh_app_config_validate
+
+    if [ "${changed[fpm_usage]}" == "true" ] || [ "${changed[fpm_footprint]}" == "true" ] || [ "${changed[free_footprint]}" == "true" ]; then
+        # If fpm_footprint is set to 'specific', use $free_footprint value.
+        if [ "$fpm_footprint" == "specific" ]
+        then
+            fpm_footprint=$free_footprint
+        fi
+
+        if [ "$fpm_footprint" == "0" ]
+        then
+            ynh_print_err --message="When selecting 'specific', you have to set a footprint value into the field below."
+
+            exit 0
+        fi
+    fi
+}
+
+ynh_app_config_apply() {
+    _ynh_app_config_apply
+
+    ynh_add_fpm_config --phpversion=$phpversion --usage=$fpm_usage --footprint=$fpm_footprint
+}
+
 ynh_app_config_run $1
diff --git a/scripts/install b/scripts/install
index c84ec01..bf4cbc1 100755
--- a/scripts/install
+++ b/scripts/install
@@ -91,7 +91,7 @@ ynh_add_nginx_config
 ynh_script_progression --message="Configuring PHP-FPM..." --weight=1
 
 # Create a dedicated PHP-FPM config
-ynh_add_fpm_config
+ynh_add_fpm_config --usage=low --footprint=low
 
 #=================================================
 # ADD A CONFIGURATION
diff --git a/scripts/restore b/scripts/restore
index 2361430..fdc2b42 100755
--- a/scripts/restore
+++ b/scripts/restore
@@ -33,6 +33,9 @@ path_url=$(ynh_app_setting_get --app=$app --key=path)
 final_path=$(ynh_app_setting_get --app=$app --key=final_path)
 phpversion=$(ynh_app_setting_get --app=$app --key=phpversion)
 
+fpm_footprint=$(ynh_app_setting_get --app=$app --key=fpm_footprint)
+fpm_usage=$(ynh_app_setting_get --app=$app --key=fpm_usage)
+
 #=================================================
 # CHECK IF THE APP CAN BE RESTORED
 #=================================================
@@ -69,13 +72,6 @@ chmod 750 "$final_path"
 chmod -R o-rwx "$final_path"
 chown -R $app:www-data "$final_path"
 
-#=================================================
-# RESTORE THE PHP-FPM CONFIGURATION
-#=================================================
-ynh_script_progression --message="Restoring the PHP-FPM configuration..." --weight=1
-
-ynh_restore_file --origin_path="/etc/php/$phpversion/fpm/pool.d/$app.conf"
-
 #=================================================
 # SPECIFIC RESTORATION
 #=================================================
@@ -86,6 +82,15 @@ ynh_script_progression --message="Reinstalling dependencies..." --weight=10
 # Define and install dependencies
 ynh_install_app_dependencies $pkg_dependencies
 
+#=================================================
+# RESTORE THE PHP-FPM CONFIGURATION
+#=================================================
+ynh_script_progression --message="Restoring the PHP-FPM configuration..." --weight=1
+
+ynh_restore_file --origin_path="/etc/php/$phpversion/fpm/pool.d/$app.conf"
+
+ynh_add_fpm_config --usage=$fpm_usage --footprint=$fpm_footprint --phpversion=$phpversion
+
 #=================================================
 # RESTORE THE LOGROTATE CONFIGURATION
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index 614d56f..e3ad44e 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -20,6 +20,9 @@ domain=$(ynh_app_setting_get --app=$app --key=domain)
 path_url=$(ynh_app_setting_get --app=$app --key=path)
 final_path=$(ynh_app_setting_get --app=$app --key=final_path)
 
+fpm_footprint=$(ynh_app_setting_get --app=$app --key=fpm_footprint)
+fpm_usage=$(ynh_app_setting_get --app=$app --key=fpm_usage)
+
 #=================================================
 # CHECK VERSION
 #=================================================
@@ -40,6 +43,44 @@ ynh_clean_setup () {
 # Exit if an error occurs during the execution of the script
 ynh_abort_if_errors
 
+#=================================================
+# STANDARD UPGRADE STEPS
+#=================================================
+# ENSURE DOWNWARD COMPATIBILITY
+#=================================================
+ynh_script_progression --message="Ensuring downward compatibility..." --weight=1
+
+# If db_name doesn't exist, create it
+if [ -z "$db_name" ]; then
+	db_name=$(ynh_sanitize_dbid --db_name=$app)
+	ynh_app_setting_set --app=$app --key=db_name --value=$db_name
+fi
+
+# If final_path doesn't exist, create it
+if [ -z "$final_path" ]; then
+	final_path=/var/www/$app
+	ynh_app_setting_set --app=$app --key=final_path --value=$final_path
+fi
+
+# If fpm_footprint doesn't exist, create it
+if [ -z "$fpm_footprint" ]; then
+	fpm_footprint=low
+	ynh_app_setting_set --app=$app --key=fpm_footprint --value=$fpm_footprint
+fi
+
+# If fpm_usage doesn't exist, create it
+if [ -z "$fpm_usage" ]; then
+	fpm_usage=low
+	ynh_app_setting_set --app=$app --key=fpm_usage --value=$fpm_usage
+fi
+
+# Cleaning legacy permissions
+if ynh_legacy_permissions_exists; then
+	ynh_legacy_permissions_delete_all
+
+	ynh_app_setting_delete --app=$app --key=is_public
+fi
+
 #=================================================
 # CREATE DEDICATED USER
 #=================================================
@@ -85,7 +126,7 @@ ynh_install_app_dependencies $pkg_dependencies
 ynh_script_progression --message="Upgrading PHP-FPM configuration..." --weight=1
 
 # Create a dedicated PHP-FPM config
-ynh_add_fpm_config
+ynh_add_fpm_config --phpversion=$phpversion --usage=$fpm_usage --footprint=$fpm_footprint
 
 #=================================================
 # GENERIC FINALIZATION