Notes about the SPEF file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The SPEF file type is primarily associated with 'SP Text Encoder' by SP Programs. If you want your text files safe from prying eyes, just copy and paste your text into the encoder, click Save. You then set a 16 character password for extra safety, and it's encoded.