When changing your account email from account settings, a confirmation email is sent to the new address, but if that address already has its own Railway account, no confirmation email is sent (the dashboard still shows the same "sent" message either way). In that case the change cannot proceed because the target address is already in use. If the email did arrive and the confirmation link appeared to do nothing, the fix is to enter your current (old) email at the sign-in prompt that appears when you click the link, not the new one, as the change only completes when you are signed in as the original account. The link expires after 20 minutes, so if it has aged out, start the change again from account settings.