If a person delivers to his friend an anonymous food package on Purim – meaning, he places it by the door without any card, note or other indication of where it is from – does he fulfill the Misva of Mishloah Manot? Does the Misva require that the recipient know who gave him the food package, or does it require simply giving a food package to his fellow?
This question hinges on the reason underlying the obligation of Mishloah Manot. There are two possible reasons for this Misva. The first is that this Misva serves to foster a feeling of love and camaraderie among people. If so, then the Misva would certainly require informing the recipient who brought the package. If a person receives an anonymous gift and has no idea at all who gave it to him, no special feelings of love and camaraderie have been engendered. According to this reason, then, one would not fulfill the Misva with an anonymous package. The other possible reason for Mishloah Manot is that it serves to provide people with food for the Purim feast. The obligation for each person to give food packages to others helps ensure that people will have provisions for a festive celebration. According to this reason, it would not seem to matter whether or not the recipient knows who gave him the food package. As long as he received food, the person who gave it fulfills his obligation.
As for the final Halacha, the Ketab Sofer (Rabbi Avraham Sofer of Pressburg, 1815-1871) and the Aruch Ha’shulhan (Rabbi Yechiel Michel Epstein of Nevarduk, 1829-1908) rule that one does not fulfill the Misva with an anonymous gift. Therefore, if one leaves a Mishloah Manot package for the recipient by his door, and does not hand it to him in person, he must affix a card or note so that the recipient knows who gave him the gift.
When it comes to Matanot La’ebyonim (the obligatory donation to the poor on Purim), however, to the contrary, it is preferable to give an anonymous donation. A needy beneficiary suffers less embarrassment when he does not know the donor’s identity, and it is therefore preferable to give one’s Matanot La’ebyonim anonymously. Many people fulfill this Misva by giving money to organizations that distribute the funds to needy Jews on Purim, and this is the ideal manner in which to fulfill this Misva.
Summary: Mishloah Manot should not be given anonymously. If one does not personally give the package to the recipient, he must leave a note informing the recipient of who gave him the package. Matanot La’ebyonim (and charity in general), however, should preferably be given anonymously.