Would you use zillow to get alert on unlisted property?

[Isaac El]

Hi,  Still new to real estate and this website has been amazing.  Doing lots of driving for dollars and leanring from all of you on the website.  

Question:

what site would you recommend to get alert on when a property gets listed? I have lots of properties I am interested in from driving for dollars, and while I am doing mailings and cold calling actively, I also want to get an alert if the property ever gets listed for sale? Would you recommend Zillow for this? or another website?

Thank you,

Isaac