Do I have to ask potential tenant recommendation letter from current landlord?

[Kevin Kim]

Hi,

We have found a really good potential tenant. He has already submitted an application through Zillow, and we have the contact number of his current home manager.

Please let me know if it's still a good idea to ask the potential tenant for a recommendation letter from their current landlord, or if calling the manager would suffice.

By the way, what should we do if the tenant has simply provided a friend’s number, and the friend pretends to be the landlord or property manager, or if he just make fake letter? Are there a way to check? 

Thank you.