Hello,
** deactivate all third party plugins with cache plugin.
** activate: https://wplms.io/support/knowledge-base/postman-smtp-for-emails/
configure it and then check if the test email goes in your wp-admin email's inbox.
** check other emails that are going or not?? like forgot password and woocommerce.
** then goto wp-admin >> lms >> settings >> emails >> set these two values.
refer: http://prntscr.com/pukpfq
if it does not work then go to wp-content / themes / wplms / functions.php by using ftp and then add this line one by one,
add_filter( 'bp_email_use_wp_mail', '__return_true' );
if it does not work then replace with this one
add_filter( 'bp_email_use_wp_mail', '__return_false' );
check if it works.
also contact your WebHost and ask them if they are blocking the email from wordpress, we are using wp_mail() function.