Update README.md

Author: samuraee

README.md

@@ -44,7 +44,7 @@ composer update
 ## ⚙️ Configuration
 ### Step 2: Set up .env variables
 ```dotenv
-MAIL_MAILER=postal
+MAIL_DRIVER=postal
 POSTAL_API_KEY=your_postal_api_key_here
 POSTAL_API_ENDPOINT=https://postal.yourdomain.com
 ```
@@ -105,4 +105,4 @@ This project is open-sourced under the MIT license.
 ## 🤝 Credits
 Made with ❤️ by Aboozar Ghaffari
 
-Postal by [Atech Media](https://postal.atech.media)
+Postal by [Atech Media](https://postal.atech.media)