The Divi contact form allows you to send to multiple email addresses by opening the properties of the form and entering multiple comma separated email addresses but they end up all in the To: field

Adding BCC to Emails using a functions.php Snippet
You need to edit your functions.php and add the below code. functions.php is located under wp-content/themes/<theme_name>/
Possible Locations of the Divi functions.php file
# if using Divi without a child theme
wp-content/themes/Divi/functions.php
# if using child theme replace 'divi-child' with whatever the directory name is of your Divi child theme.
wp-content/themes/divi-child/functions.php
The following code snippet allows you to silently add another email address to emails sent from your WordPress site as a BCC
<?php
add_filter('wp_mail', 'custom_mails', 10, 1);
function custom_mails($args)
{
$bccEmail = sanitize_email('[email protected]');
# e.g.
# $bccEmail = sanitize_email('[email protected]');
if (is_array($args['headers'])) {
$args['headers'][] = 'Bcc: ' . $bccEmail;
} else {
$args['headers'] .= 'Bcc: ' . $bccEmail . "\r\n";
}
return $args;
}
This is the original website I got this code from

doesn't work.
From the emails I get from Divi powered websites all over the world because people have forgotten to take my email address from the code I respectfully disagree ;).
Are you sure you are putting the code in the right place?
Do you have email working from the website itself?
To check this you can install a plugin such as Check & Log Email https://check-email.tech/ by checkemail and try and send a test email. If your email isn't working, typically neither will the above code.
If email is not working, here are some options to get emails from your forms: