The Income Tax department has identified 18 lakh people who have made 'suspicious' cash deposits post demonetisation, including those having deposited over Rs. 5 lakh, and will send emails and SMSes seeking explanation about their source of funds. These people will have to reply within 10 days to avoid any notice from the tax department or further enforcement action. The department on Tuesday launched 'Operation Clean Money' project under which CBDT, with data analysis and profiling of assessees, will send e-communications to people whose cash deposits post November 8 note ban do not match their income.