Shulchan Aruch (EH 21:6) says that one may not ask a married woman about her welfare, even via a messenger, and even via her husband. (Based on Bava Metzia 87.)
The SA does not say “married.” It doesn’t say “Ain Shoalin Bshlom Aishes Ish Klal.” It says “Ain Shoalim Bshlom Isah K’lal.” It seems to me that it should be forbidden to ask about a non-married woman too. Furthermore, the fact that the word “Klal” (at all) is included indicates to me that there are NO exceptions.
That’s why I’m such a perverted sick human being. The other day I asked my wife about my daughter’s doctor appointment and I asked my sister how my neice was doing at camp. I realize that I should not have done those things and that I should be shunned by the community as a deviant for these disgusting acts that are clearly in violation of the Shulchan Aruch.
The Wolf