It hasn't been possible for many months, @Jayshanjit, and no solution in sight.
Staff can do some things manually - they'll be back on here during the day, Monday to Friday.
It's helpful if you can complete your community forum profile details for them to identify your account.
Go via your avatar; settings; drop down menu. Put your Talktalk phone number or account number in Personal Information. In Private Notes, near the end of that area, add the email address you want to add. SAVE CHANGES.
Gliwmaeden2, a fellow customer.
