Hey Frederick, To my knowledge there are some best practices but its ot illegal to direct mail anyone.I found this from article that might be helpful with the specifics:"There is no law in the US that prohibits direct mail marketing on either state or national level.

LESS THAN 7 DAYS PROHIBITED: Short-Term Rentals for less than 7 days areprohibited."

The long period of expansion prohibits the federal reserve from significantly lowering rates again.

The sale will be conducted subject to (1) confirmation that the sale is not prohibited under the U.S.

Areas prohibiting STRs is an indication that they don't want them. 

I was under the impression that AZ law prohibited cities from regulating STRs? 

. :-) ADU laws are changing in Utah all the time:H.B. 82, sponsored by Representative Raymond Ward, addresses this issue and helps alleviate the problems caused by the housing crisis.The bill prohibits local and state governments from establishing accessory dwelling unit restrictions regarding things like the size of the unit, the size of the lot, parking, and street frontage.

Does your mortgage with the first lender prohibit you specifically from getting a second?

There are FEDERAL laws that prohibit activating the due on sale clause under certain circumstances. 

Accessory Dwelling Unit/in-law unit requirements)A: Current planning regulations prohibit any rental of a single-family home, duplex, apartment/condo, live/work unit, or room for less than thirty (30) days, based on the City’s definition of “Permanent Residential Activities”, which are defined as the occupancy of living accommodations on a thirty (30) days or longer basis, with none of the living units under the same ownership or management on the same lot being occupied on a shorter basis.If you are renting your single-family home, duplex, apartment/condo, live/work unit, or room for less than thirty (30) days, the Oakland Planning Code defines the activity as “Transient Habitation” (or essentially a hotel).