Courtesy of Ohr Olam Mishnah Berurah
Question: Is it permissible to send an overnight letter or package (via the Postal Service or UPS, etc.) on Friday with specific instructions to deliver it on Shabbos?
Discussion: Amirah l’akum, instructing a non-Jew to perform a Shabbos Labor which would be forbidden for a Jew, is prohibited. It makes no difference whether the Jew’s command is given on or before Shabbos. Accordingly, it should be forbidden to instruct a non-Jew on Friday to deliver an overnight package on Shabbos, since there are several prohibitions involved in delivering mail on Shabbos.
When necessary, however, there is room for leniency. Some poskim hold that only a direct command to a non-Jew is forbidden; instructing a non-Jew to instruct another non-Jew — amirah l’amirah — is permitted. Not all poskim agree with this leniency. Mishnah Berurah rules that one can rely on this view to avoid a major financial loss (hefsed gadol). Other poskim rule that one may rely on this view in a case of great need (tzorech gadol). It follows, therefore, that one is permitted to send an overnight letter with a delivery company to be delivered on Shabbos in case of great loss or great need, since the command to deliver the item is not given directly to the delivery man but rather to another non-Jew.
There are other arguments for permitting one to have a letter delivered on Shabbos:
- Chasam Sofer rules that even those who prohibit instructing a non-Jew to instruct another non-Jew would permit it if the Jew’s instructions to the first non-Jew were given before
- Some poskim argue that mailmen working for a governmental Postal Service (or for a private company) do not work for the sender but rather for the Service, which has an interest in mail being delivered. They are not delivering the mail because the Jew asked them to do so, but because they are employees of the Service. They are not considered, therefore, as doing something for the Jew. Mail delivery is similar to garbage collection in which the garbage men are not working for the homeowner but rather for the city government or for the private company.
These reasons are sufficient to permit a letter to be sent with instructions to deliver it on Shabbos, even when the situation is not necessarily one of averting a major loss or filling a great need. Nevertheless, if there is no need or urgency, it is better not to rely on the above arguments.
 This is a Rabbinic prohibition. According to a minority opinion, it is a Biblical prohibition; see Sha’ar ha-Tziyun 243:7.
 O.C. 307:2.
 See Chelkas Yaakov 1:65.
 Chavos Yair 53.
 307:24, quoting the Sefer ha-Chayim.
 Maharsham 2:136, quoting the Shvus Yaakov 2:42.
 Maharsham 2:136, and in Da’as Torah 247:1; Az Nidberu 3:36.
 O.C. 60.
 See Beiur Halachah 307:2, who quotes this Chasam Sofer and comments that from the Rashba it seems that this is not so, that amirah l’amirah is forbidden even during the week. But see Zichron Yosef 97 (quoted in Machazeh Eliyahu 37) who explains that there is no contradiction between the Rashba and the ruling of the Chasam Sofer; the Rashba referred only to a case where the first non-Jew is required to instruct the second non-Jew specifically on Shabbos. If he is able to instruct him before Shabbos, but chooses to do so on Shabbos, it is permitted.
 Pri Megadim 247:3 according to the explanation of Machazeh Eliyahu 37.
 See Minchas Yitzchak 6:18, who is hesitant about permitting this, although he concedes that many people are lenient.