message sent but does not show in inbox or spam

This is happening to me, too. As of two weeks ago.

The green box and not receiving any error messages is a very clear indication that CF7 is sending the email.

So your email is probably being seen as spam somewhere in the email process. This is usually due to email headers (in particular the From email address used) or email content.

Important to remember there are a lot of places, other than your spam folder, where emails can be trapped as spam.

See Contact Form 7 Email Issues – this links to a much more comprehensive article which also covers emails being considered Junk.??