What version of Premiere Elements and on what computer operating system is it running?
What is the bitrate of the source and what is the bitrate in the export settings for Windows Media?
Do the videos have no sound because there is no sound included in the file or are you losing sound in the export?
What is the maximum flle size accepted in your emailing process?
Is something like Dropbox or Google Drive an option for the sending?
If your preference is high definition and your concern is file size, bitrate settings need to be explored to find the compromise between file size, bitrate, and quality. Depending on the circumstances, you need not be forced into standard definition to obtain a file size that will meet your requirements and give acceptable quality.