mstudioIL on "[Plugin: WP Mail SMTP] Some help with result"

When I using "Send all WordPress emails via SMTP." I getting bool(false)
When I using "Use the PHP mail() function to send emails." I getting bool(true) but I still do not receive any mails.
I using contact form 7 and some of the explains I found is to use this plugin to set smtp, I read the note of contact form 7 and I getting the green border that said the message sent, can the problem be with the hosting?
I using register.com

https://wordpress.org/plugins/wp-mail-smtp/