Using Zillow messanger to contact FRBO listings

I’m a new property manager and I’m trying to get my first clients.

The way I’m thinking is to use Zillow and message all the for rent by owner listings using their built in messenger. The reason I want to use the messanger is because most numbers from landlords are showing up on the Do Not Call Registry. Is this allowed on Zillows platform or would they ban my account? Are there any other ideas on how I could use Zillow FRBO listings to convert to warm leads?

Thank you guys!