IM Global LLC review: Third party shipper

On May 1, 2023, I received an envelope from the above-referenced third-party shipper which contained nothing inside other than the following typewritten message on a small square of white paper (no logo): “Dear valued customers – How are you today? Your item is in another package and usually arrives within 1-7 working days. Thank you very much for your purchase – we really value your business.” The tracking label for this envelope was created on April 12th but did not start moving in the post until April 22nd. This company has a website; however, after four requests to confirm the name of the actual Seller/Sender who supposedly sent me the shipment in question, it appears no one cares to answer me. Why not? Why send an empty envelope with a small slip of paper stating the real shipment will arrive in 1-7 days and then not explain themselves? Is this a legitimate business enterprise or a scam?