Send email confirmation from app

Hey, I’m looking the best approach to send email from Flow app. I’m creating app like booking calendar so user can select the date/time to book an appointment. Once user send booking form, it should be notified by email with appointment details. In google I can find many ways to send emails but not sure what would be the easiest way for Vaadin Flow? Can you recommend good approach?

PS. For now, I’m probably going to use some gmail account.

Anything google says is applicable for Vaadin Flow, e.g. https://www.baeldung.com/spring-email