Add “Test Email” button in SMTP configuration and email templates

[nappalm]

It would be great if the SMTP email configuration included a button to send a test email using the current settings. Even better if that same button were available within the email templates, allowing you to validate the design and delivery instantly without having to go through the full account creation flow or wait for a real email. A simple “Test Email” button would make the process much faster and more efficient.