Work with them to resolve the situation.If they abandon the property, you'll have to deal with it according to state law.This is an example of why it's important to keep an emergency contact on file for every tenant and keep it updated.

Is it important to change up direct mail messaging after each touch? 

In addition to that, having passive income is important to me.

They know people, including who is good at getting offers accepted, which is by far the most important part of RE in the Bay Area since everything gets 20+ offers.

And most importantly a huge supply gap. 

They are leaving so inconveniencing them is of less importance.

also important to clarify that it’s verifiable income, usually meaning some sort of salary.If someone shows you a bank statement with a bunch of cash or claims to be self employed making 500k a year but wants to live in your 750 a month rental obviously you should be skeptical.  

Important to note, there is a distinction between capitalization rate of properties listed for sale and properties that have closed.

My family knows where I keep them.I don’t keep track of my expenses or accounting on diary just important contacts , events, maintenance, dates etc

I think taking ACTION is the most important step you need to do.2.