For non-Setel customers, an email will be sent to the email registered to your Mesra account.
For Setel customers, you can check for expiring Mesra points by tapping Rewards. Any expiring points will appear along with the expiration date. Mesra points generally have a 3-year expiry date from the date it was earned. However, Mesra points gained from promotions and events are subject to the promotion's terms and conditions.