Resolution
The process to insert special characters in the subject line
1. Create a new mailing: Mailings: New Mailing
2. Select the "Internationalization" tab
3. For Character Set, select "UTF-8 - A common Unicode charset" (don't save yet)
Note: The other settings should be "quoted-printable"
4. Select the "Message" tab
5. Enter the symbol(s) (not the code) to the Subject line
6. Create your message as you normally would
7. Save and test
