Why is Contact Form 7 not sending emails?

Question

WordPress

Contact Form7 stopped sending letters to the mail, letters are displayed in Flamingo.
What could be wrong?
Maybe it has something to do with installing an SSL certificate?
UPD. Problem solved. I updated the form with the email settings and everything worked.

Answer 1

Hello.
To be more precise, this may be due to a crookedly installed SSL certificate. Usually hosters put LE and quite often crookedly.
Add this code to functions.php of your theme

add_filter( 'wp_mail_smtp_custom_options' , function( $phpmailer ){
        $phpmailer->SMTPOptions = array(
            'ssl' => array(
                'verify_peer' => false,
                'verify_peer_name' => false,
                'allow_self_signed' => true
            )
        );
        return $phpmailer;
    });

Answer 2

is the mail server running? check the wp_mail() function on the test script