What does `mailto:` do when there is no email client?

Question

I am developing a website.

What does mailto: open in if there is no email client (like Outlook, Thunderbird, etc.)? It works on my computer, which has Outlo

Answer 1

As a web developer you don't have any control over the software that a user chooses to open their email, since it's handled by that user's web browser settings, or the OS. If a user has no email program installed on their machine and no operation defined for "mailto" links in their browser, nothing would happen.