Double-check the following:
1) In Site Admin -> Site Projects, verify ''Send Mail Automatically'' is checked in your project's ''Project Details'' tab.
2) In Site Admin, expand your project's database tables, then navigate to the `DATACONST` table. Make sure you have a `FROM_EMAIL_ADDRESS` parameter with an appropriate/valid email address. If you need to add one, execute the following SQL (replacing `firstname.lastname@example.org` with the valid email address):
INSERT INTO DATACONST VALUES ('FROM_EMAIL_ADDRESS', 'email@example.com')
*If there's already a `FROM_EMAIL_ADDRESS` parameter, but you need to change the value, run an `UPDATE` instead:
UPDATE DATACONST SET DC_VALUE = 'firstname.lastname@example.org' WHERE DC_CONST_NAME = 'FROM_EMAIL_ADDRESS'
3) In Site Admin -> Site Configuration, make sure your `MAIL_INTERVAL` site parameter's value is set to at least 10, which is the minimum QC will allow.
4) In QC, log into your project and go to Project Customization (Tools -> Customize) to verify the selected Defect Fields, users, and filter conditions in the Automail section.