How can I check if a message has been read?

Is it possible to know if the messages I have sent to my users have been read?

If you have contacted your customers by commercial SMS, it is not possible to confirm if the message has been read. You can check the 'delivery status' (see the status page) to confirm delivery. However, if you use WhatsApp Business or Rich SMS (RCS), you will have more information on whether the message has been read.