Hi,
To get your IMEI number via SMS, you will need to create a new SMS rule (or modify an existing one, like the 'status' rule) in Services -> Mobile utilities -> SMS utilities. Include the IMEI text message. Refer to image attached.
In the example, you will be able to send SMS with the command 'imei' and it will return the imei number.
Kind Regards,
Andzej