To ‘xmit’ a file in the mainframe, you must execute the TSO command RECEIVE INDATASET(???). XMIT files are binary data set that have the extension.XMI. Before they can be used, they must first be converted to PDS. If you want to convert XMIT files back to sequential files, use the 7-Zip file-unzipping application.
To export an XMIT file from the mainframe, use one of two methods. The first is to use a Hercules card punch to transfer the XMIT data to the host computer. The second method is to use IND$FILE which is a batch job that extracts XMIT content into a recreated data set.
After installing the application you will need to associate it and XMIT files by making it the default application. This process varies by platform, but the basic process is the same. When you select an XMIT file in a file directory, you should be prompted with a message window informing you that you have successfully associated the format with your default application. Click Continue to confirm the change. In some cases, you may need to verify the file before you can use it.