Is there anything else I need to configure besides the Properties of the auto generated form?
The only setup to use the PHP mail() function is to have a valid Email address in your x10hosting's free-hosting account
external [ SMTP ] is blocked on x10hosting's free-hosting servers - all Email must go out through outbound spam filters on 10hosting's SMTP server - to be scanned for spam and phishing and other test - messages with no body content - and HTML-only mail (mail with no plain text part) - and messages with no subject - and messages that just say "Testing" (or like that) - and anything else that looks "spammy" (as far as the outbound mail filters are concerned) will be silently discarded - or sometimes the transfer to the SMTP server fails - you will not receive any notice when it fails
spoofing the [ From ] header is not allowed - Emails with the [ From ] header not set with a working Email address that exists and is actually part of your x10hosting's free-hosting account will be silently discarded - you will not receive any notice when it fails
you can not set the [ From ] header to a user's email address or to your own external email address - if you need to easily reply to the emails - then set the [ Reply-To ] header (which can be different from the [ From ] header)