Occasionally we’ve had customers with issues related to the email sent date being incorrect. This appears to be related to the DB time being incorrect. As an alternative, you can set the following in your wp-config.php file to use the server’s UTC time instead of the DB time.
Before doing this, do double check that the universal/local time is displayed correctly beneath the timezone dropdown in the settings WP Admin > Settings > General > Timezone
// WP Sent Mail - Use server time instead of DB time for emails
define( 'WPSM_USE_SERVER_TIME', true );