Hi there @monicaamb12,
Thanks for reaching out.
The term “On Hold” in WooCommerce Subscriptions means that the subscription is temporarily paused. This could be due to a variety of reasons, such as awaiting payment, or if the customer or store manager has manually put it on hold. You can learn more from the official guide here: https://woocommerce.com/document/subscriptions/statuses/#section-3
And also what email is sending to the customer? Can I see and history of the email are sending to the customers in this cases?
When a subscription is put “On Hold”, an email is sent to the customer to notify them of the change in their subscription status. The content of the email can be customized under WooCommerce > Settings > Emails > On Hold Renewal Order.
As for the email history, WooCommerce does not natively store sent emails. However, there are several plugins available that can help you with this, you can run a quick search from the plugin repository for such plugins. This allows you to view a log of all emails sent from your store, including those related to subscriptions.
I hope this answers your questions. Please feel free to reach out if you have any more queries.