How do I properly send out mail for off-market properties?

[Ellie Narie]

I am looking for off market 4plexes in my area. I have located a street where there are a bunch of them, so I am just looking up the addresses and the owner's names and contact info from public records (whitepages, spokeo, etc). I don't know how accurate the addresses are, but if there are two owners (most of the time a married couple), then I compare the addresses for both of them and send to the matching one. I got a free trial on spokeo to look up contact info. There are a bunch of emails that come up with my searches, should I try to send an email as well as a letter in the mail? Does this feel a bit "stalker-ish"? Or is this what it takes to get an off-market multi-family property? 

Also, for the properties that have two owners (usually a couple), should I send out a letter in each of their names?