What configuration and setup is required for sending emails via your website?

If you are asking what is needed, there are multiple ways to do it. Simplest is to have just link with mailto: attribute, that opens end-users default email client with prefilled "to" and "topic" fields (optionally "cc" and "bcc" fields as well). This relies that users have email client configured (mobile users have, desktop users not necessarily). Anything deeper needs a bit more explanation of what you are asking? Who is sending emails, and who should be receiving them? Forms and their backend scripts are one way for website visitors to send emails. And those scripts can be made in many ways. Or you could make user submit their email to your database, and then use external applications/services to handle actual email sending.