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

The mailto URI scheme doesn't decide what happens-- it simply instructs the browser you're using to do whatever it's been configured to do to send e-mails (see the IETF proposed standard for more info). Therefore, you'll have to consult the browser itself to see what it does if no e-mail client is configured.

According to the documentation and to my personal experience, I don't see any way of manually setting an action: It might be possible with certain browsers with some non-standard syntax, but this is unlikely since this would open up a huge potential security problem by being able to execute an arbitrary command by click (such as downloading a virus or something like that).