I think that Zillow more or less requires it, so your solution of putting the information number in is probably your best option, or even an automated message that instructs callers to email, text, just start the auto process, or whatever else you want them to do may be helpful.  

Should I stop mailing those angry callers or should I be persistent hoping they realize that I want to help?

But I was happy to get prospects from them calling, since those prospects tended to be better quality in my area then the Craigslist callers.

As a full time firefighter my understanding and the person we approach if we receive fraudulent calls is the caller/resident.

You avoid the bored CL tire kicking bored potential phone caller who likes to make an appointment for viewing but then no shows.......

Talk about taking caller ID to a new level!

The callers have received numerous garish REI letters, and they call me, thinking I might be less scary to deal with as an individual.

I'm hiring my first cold caller right now on the platform.

When I first started, I got a bunch of calls asking if I would accept someone who "gets a check"  and a caller actually explained that they meant social security disability income (SSDI)-- you know, a 'crazy' check. 

I don't want to be like the client everybody rolls their eyes when the number comes up on caller ID, but I also don't want to be put to the back of the line because I don't have 35 properties under their management.