Hoo: um_email_send_message_content

um_email_send_message_content.php

<?php

/**
 * Hook: um_email_send_message_content
 *
 * Type: filter
 *
 * Description:  Change email notification body.
 *
 * @example https://github.com/ultimatemember/ultimatemember/blob/master/includes/core/class-mail.php#L381
 *
 * @package um\core
 * @see     um\core\Mail::prepare_template()
 * @since   2.0
 * @version 3.0
 *
 * @param string $message  Email body.
 * @param string $template Template key.
 * @param array  $args     Template settings.
 *
 * @return string Email body.
 */
function my_email_send_message_content( $message, $template, $args ) {
	// your code here.
	return $message;
}
add_filter( 'um_email_send_message_content', 'my_email_send_message_content', 10, 3 );