Forces the BP email content to be HTML

bp-custom.php

<?php
/**
 * @see https://buddypress.trac.wordpress.org/ticket/8104
 * @see https://buddypress.trac.wordpress.org/ticket/8108
 * @see https://buddypress.org/support/topic/buddypress-email-notification-ignoring-smtp-server-settings/
 */

function shawfactor_use_html_wp_mail() {
	return 'text/html';
}
/**
 * If you're using a plugin to send emails using wp_mail, it may
 * already force HTML.
 */
add_filter( 'wp_mail_content_type', 'shawfactor_use_html_wp_mail' );

function shawfactor_get_bp_email_content_plaintext( $content = '', $property = 'content_plaintext', $transform = 'replace-tokens', BP_Email $bp_email ) {
	// Make sure we're about to send an email.
	if ( ! did_action( 'bp_send_email' ) ) {
		return $content;
	}
	
	return $bp_email->get_template( 'add-content' );
}
add_filter( 'bp_email_get_content_plaintext', 'shawfactor_get_bp_email_content_plaintext', 10, 4 );