diff --git a/.docker/frankenphp/docker-entrypoint.sh b/.docker/frankenphp/docker-entrypoint.sh
index 1655af5a..ff1fbb69 100644
--- a/.docker/frankenphp/docker-entrypoint.sh
+++ b/.docker/frankenphp/docker-entrypoint.sh
@@ -26,6 +26,18 @@ if [ "$1" = 'frankenphp' ] || [ "$1" = 'php' ] || [ "$1" = 'bin/console' ]; then
 		composer install --prefer-dist --no-progress --no-interaction
 	fi
 
+	# Install additional composer packages if COMPOSER_EXTRA_PACKAGES is set
+	if [ -n "$COMPOSER_EXTRA_PACKAGES" ]; then
+		echo "Installing additional composer packages: $COMPOSER_EXTRA_PACKAGES"
+		composer require $COMPOSER_EXTRA_PACKAGES --no-interaction --no-progress --optimize-autoloader
+		if [ $? -eq 0 ]; then
+			echo "Successfully installed additional composer packages"
+		else
+			echo "Failed to install additional composer packages"
+			exit 1
+		fi
+	fi
+
 	if grep -q ^DATABASE_URL= .env; then
 		echo "Waiting for database to be ready..."
 		ATTEMPTS_LEFT_TO_REACH_DATABASE=60
diff --git a/.docker/partdb-entrypoint.sh b/.docker/partdb-entrypoint.sh
index f5071e22..94d7f0f6 100644
--- a/.docker/partdb-entrypoint.sh
+++ b/.docker/partdb-entrypoint.sh
@@ -39,6 +39,18 @@ if [ -d /var/www/html/var/db ]; then
     fi
 fi
 
+# Install additional composer packages if COMPOSER_EXTRA_PACKAGES is set
+if [ -n "$COMPOSER_EXTRA_PACKAGES" ]; then
+    echo "Installing additional composer packages: $COMPOSER_EXTRA_PACKAGES"
+    sudo -E -u www-data composer require $COMPOSER_EXTRA_PACKAGES --no-interaction --no-progress --optimize-autoloader
+    if [ $? -eq 0 ]; then
+        echo "Successfully installed additional composer packages"
+    else
+        echo "Failed to install additional composer packages"
+        exit 1
+    fi
+fi
+
 # Start PHP-FPM (the PHP_VERSION is replaced by the configured version in the Dockerfile)
 php-fpmPHP_VERSION -F &
 
diff --git a/docs/installation/installation_docker.md b/docs/installation/installation_docker.md
index 347c2451..b7048169 100644
--- a/docs/installation/installation_docker.md
+++ b/docs/installation/installation_docker.md
@@ -80,7 +80,11 @@ services:
       #- BANNER=This is a test banner<br>with a line break
     
       # If you use a reverse proxy in front of Part-DB, you must configure the trusted proxies IP addresses here (see reverse proxy documentation for more information):
-      # - TRUSTED_PROXIES=127.0.0.0/8,::1,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16  
+      # - TRUSTED_PROXIES=127.0.0.0/8,::1,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16
+      
+      # If you need to install additional composer packages (e.g., for specific mailer transports), you can specify them here:
+      # The packages will be installed automatically when the container starts
+      # - COMPOSER_EXTRA_PACKAGES=symfony/mailgun-mailer symfony/sendgrid-mailer
 ```
 
 4. Customize the settings by changing the environment variables (or adding new ones). See [Configuration]({% link
@@ -149,6 +153,9 @@ services:
       # Override value if you want to show a given text on homepage.
       # When this is commented out the webUI can be used to configure the banner
       #- BANNER=This is a test banner<br>with a line break
+      
+      # If you need to install additional composer packages (e.g., for specific mailer transports), you can specify them here:
+      # - COMPOSER_EXTRA_PACKAGES=symfony/mailgun-mailer symfony/sendgrid-mailer
 
   database:
     container_name: partdb_database
@@ -169,6 +176,38 @@ services:
 
 ```
 
+### Installing additional composer packages
+
+If you need to use specific mailer transports or other functionality that requires additional composer packages, you can 
+install them automatically at container startup using the `COMPOSER_EXTRA_PACKAGES` environment variable.
+
+For example, if you want to use Mailgun as your email provider, you need to install the `symfony/mailgun-mailer` package.
+Add the following to your docker-compose.yaml environment section:
+
+```yaml
+environment:
+  - COMPOSER_EXTRA_PACKAGES=symfony/mailgun-mailer
+  - MAILER_DSN=mailgun+api://API_KEY:DOMAIN@default
+```
+
+You can specify multiple packages by separating them with spaces:
+
+```yaml
+environment:
+  - COMPOSER_EXTRA_PACKAGES=symfony/mailgun-mailer symfony/sendgrid-mailer
+```
+
+{: .info }
+> The packages will be installed when the container starts. This may increase the container startup time on the first run.
+> The installed packages will persist in the container until it is recreated.
+
+Common mailer packages you might need:
+- `symfony/mailgun-mailer` - For Mailgun email service
+- `symfony/sendgrid-mailer` - For SendGrid email service  
+- `symfony/brevo-mailer` - For Brevo (formerly Sendinblue) email service
+- `symfony/amazon-mailer` - For Amazon SES email service
+- `symfony/postmark-mailer` - For Postmark email service
+
 ### Update Part-DB
 
 You can update Part-DB by pulling the latest image and restarting the container.