IMIconnect doesn't provide an inbox or an interface for viewing incoming SMS.
However, you can forward the messages to your own applications by configuring a Message Outbound (MO) forward URL in the General Settings under a service.
You will also need to own a long number or a short code or a keyword and then map it to service under service settings before the messages are forwarded to the configured URL.
For more information on call-backs and corresponding formats, visit docs.
We also have a guide on sending and receiving SMS here.