Q. If someone sends a box of kosher chocolates or cookies that are not Cholov Yisroel, to someone that is machmir and does not eat them. Is the sender, who does eat those foods yotze mishloach monos?
A. Chashukei Chemed (Megila 7a) quotes Machane Chaim (3: 53) that is in doubt whether we follow the minhag of the giver, who is lenient on cholov Yisroel, or the opinion of the receiver, who isn’t. He mentions that it depends on the rationality for sending shalach monos. Poskim mention two main reasons for the mitzva of mishloach monos. Trumas Hadeshen (111) maintains it is for the purpose of all having the necessary food available to comply with the Purim seuda. However, Manos Halevy asserts that it is to increase and support friendship and peace. He maintains that even according to the second opinion, since the receiver will not consume them, it may be similar to just sending him an inedible object and he does not comply. He remains in doubt.
Horav Shlomo Miller’s Shlit’a opinion is that one should be stringent. The Rov added that there may be an additional issue of “messayea lidvar avera” or causing someone to commit a prohibited act (to him).
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a