Common sense will eventually win, just be persistent.

👊🏽 To succeed in real estate takes patience, persistence and strategic planning

It's a disease I tell you.

They persist even when I explain that if they can't speak English they can't sign the lease.

Long story short, three of her siblings died young of heart disease brought on by terrible diets, smoking, and drinking.

Finding the opportunity isn't obvious or free, per se, but there's no reason you can't leverage your networking or dogged persistence to do it.Money, Opportunity, and Execution form the triad of a successful investment. 

Use a stock reply telling them the open house time.I have ignored obvious scams and on one occasion a previous tenant but if they are persistent you have to deal with it and I usually try to reply.

I had some persist on building nests on the awnings over my windows of my apartment.  

Now, due to the fact that mold poisoning mimics many other diseases/ illnesses, this poisoning is commonly mistaken for a myriad of other illnesses, or as something in your head.

A great way to avoid potential conflict when this arises would be to set expectations upfront.Include this in a discussion: "in the situation where the heat goes out, hot water heater busts, etc, we will be given 48 hours to rectify said issue; you will be refunded rent for any time past 48 hours that the issue persists"Or something like that...