eml2mbx is a program for Windows 95/98/ME/NT/2000/XP/Vista, that packs separate plain text e-mail files (including all attachments) into mbox files, see also examples of e-mail conversion.
Installation is not required, just unpack the files in the ZIP archive to a directory on your hard disk or e.g. on your USB flash drive. Change the settings in the INI file if you want.
eml2mbx doesn't add entries to the Windows registry, nor does it alter anything else on the system.
Just delete the files.
Plain text e-mail files (according to RFC 2822 ) typically have the extension EML or MSG. This is just a convention. eml2mbx can process all these files, it's not necessary to rename them beforehand. The mail files remain unchanged.