You may have been in a situation where you have an OFT template but want to use it in Gmail. I have faced exactly the same problem. As OFT files are Outlook template files, Gmail does not support them directly, i.e., one cannot upload and open them as they are. One of the manual solutions is to first open the OFT file in Outlook and then convert it into EML. After that, you can use supported methods to import or open the EML file in Gmail. However, this approach is time-consuming and might lose you data during the conversion process, especially if there are many files.
To make the process easier and avoid data loss, I chose to use a tool that can easily convert. I tried Softaken OFT Converter, which allows performing OFT to EML conversion or even exporting the OFT files directly into an IMAP account (e.g., Gmail). This way, the emails are read in Gmail without any compatibility problems.