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.
