Translation:Dobrzy ludzie wysyłają im jedzenie.
Does 'posyłać' also fit here?
Yeah, I believe so. Added.
wouldn't "przesyłają" work just fine?
Yes, true. Added now.
What is the reason "Dobre osoby" doesn't work here?
It's hard to explain why, but it doesn't seem to suit this sentence in my opinion. One of the admins also thinks the same. Maybe this is because this sentence is so general...
My views on 'person' and similar: https://www.duolingo.com/comment/19428542 - maybe it can help.
Could i use "odsyłają" instead of "wysyłają" in this sentence?
"odsyłają" is rather "send back", as in 'they didn't want it, they sent it back'.