@stewart You are calling the sendEmail() function with the name and not the email address. This is your code:
sendEmail(
$w("#nameinput").value,
$w("#emailinput").value)
However, the first parameter should be the To: email address (recipient), and the second parameter is the From: email address (sender). I your code you are passing the recipient’s name and not the email address to the sendEmail() function.
I hope this helps,
Yisrael