@rburwell,
The PHP warning about "Undefined array key 'HTTP_HOST' in media.php on line 1419" is not directly related to the wpForo email system. Regarding wpForo emails, wpForo itself does not send emails directly but queues them to WordPress core. If emails like password reset are not sent or received, it is usually a WordPress email or SMTP configuration issue rather than a wpForo issue. You should use an SMTP plugin with logging for WordPress to diagnose and fix email sending problems. The 'HTTP_HOST' warning suggests that the server environment or request context might be missing this header, which could be a separate issue in your setup or plugin/theme code. To resolve the email problem, focus on WordPress email settings and SMTP configuration.