I now have to throw up my hands in despair and surrender to Google... 
I could not afford to get a SSL certificate for all my domains (and they are 20-30 years old) but up to this year it didn't cause much of a problem. But now Google has tightened up and I'm getting blocks on my emails as well as "security alerts" for my websites. 
Trying to turn on "less secure apps" to get my gmails resulted in the message: "Less secure app access-
This setting is not available for your account."
So it's over