You can configure your Stripe account to send automatic email notifications to your customers when they have a credit card on file that is about to expire. You can enable this feature by following the steps below:
Login to your Administrator account on Stripe.
Click the "Gear" icon to go to the Settings page.
Under the "Billing" section of the "Product Settings" page, click on "Subscriptions and Emails".
Scroll down to the "Prevent Failed Payments" section and enable the "Send emails about expiring cards" setting.
Save your changes.
The image below displays the setting within the "Prevent Failed Payments" section: