Translation:Shulchan Aruch/Orach Chaim/247
247: Law of Heathens Who Bring Letters on Shabbat.
1
A person sends a letter with a heathen, and even on the eve of Shabbat close to dark, and that is provided that he specifies his wages and only so long as he won't tell him that he should travel on Shabbos. And if he did not specify, if there is not an established Bay Do'ar (meaning, a known person that every letter is sent to him and he delivers them to whom they are sent) in town, it is forbidden to send even from Sunday. And if there is an established Bay Do'ar in town, he sends even on the eve of Shabbat, and that is provided that there should be enough time remaining in the day that he should be able to reach the house adjacent to the city wall.
Gloss: And there are those who permit even if he did not specify and even if there is not an established Bay Do'ar in town if he sends it on Thursday or prior to this (Tur). And there is basis to rely on this if it's necessary.
2
And if he stipulated with him that he will give him his wages, even though he didn't clarify how much he'll give him, his law is like one who sets a price, since the heathen is depending on it and is taking the effort for his own sake. But if he didn't mention it, even though his intention is that he'll give him wages, it is forbidden since he isn't depending on it and is taking the effort for the sake of the Jew.
3 If he employed him daily, something fixed every day when he travels and when he returns, but he isn't particular with him regarding when he should travel, if it's the eve of Shabbat, then it's forbidden because when he leaves on Shabbat, it appears as if he stipulated with him as such.
4 (If) the heathen carries the letter for free, even if he gave it to him on the eve of Shabbat, it is permitted because the heathen is doing this on his own and it is only to return favor to the Jew because of what he received from him, and it is as if he established a price. Gloss: And there are some who disagree and they maintain that anyone who does it for free is prohibited. And it's good to be stringent. But in a place where the heathen takes the initiative with the Jew saying that he'll travel for free, certainly his intention is on the benefit that he received from him and it's permitted. (Beis Yosef).
5 If the heathen is traveling to another location on his own accord and a Jew gives him a letter, it is permitted in all cases.
4 One who employs a heathen for the period of a year or more is forbidden from sending a letter with him on the eve of Shabbat. Gloss: However, if he is only employed for letter-carrying, there some who permit, as it was established prior in Siman 244, section 6.