I also got on this when I had to send an OFT file to people who didn't use Outlook. OFT is an Outlook template format, and other email clients cannot open it directly. Simply sending the OFT file did not help, as the recipients could not get hold of the content. 

First, I tried opening the OFT file in Outlook and saving it in another format, like EML or MSG, so it could be shared more easily. That's only possible if Outlook is installed on a device, which isn't always convenient, especially when there are multiple files. For simplicity, I used an OSTtoPSTAPP OFT converter. It helped me convert the OFT file to the formats supported by different email clients. After conversion, I could share the file without any compatibility issues.