Q. A religious school…advertised a mishloach monos campaign… Many in the community rely on this method of fulfilling the mitzva of mishloach monos. This year the school delivered the monos on Thursday, Taanis Esther. As such have these senders fulfilled the mitzva of mishloach monos.? If not, should the school advise everyone concerned that they have not fulfilled this mitzva?

A. Horav Shlomo Miller’s Shlit’a opinion is that you do not comply with the mitzva of mishloach monos when they were not received on Purim. However, they could possibly be sent before if the senders have in mind that the receivers should not to acquire them until Purim, and the receivers are informed not to consume them before Purim. (as was mentioned on question 1275 in regards to matonos laevyonim).
Although, it is most common for people to send or give back small mishloach monos numerous times during Purim, in principle the school should have notified the receivers of the untimely delivery, The Rov mentioned also that even if you may not comply with this premature gift the mitzva of mishloach monos, it is still a mitzva as one performed an act of kindness.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a