In the case of receiving (in your sentence), に and から are interchangeable.
From a different imabi article:
Particle Note: For “to give”, に is used to mark the recipient while for “to receive”, the giver is marked by に. For the latter, から may be used instead. から, unlike に, may also be used with “receive” aside from an actual person.
In order to to use から with a na-adjective or noun, you have to have the だ between the noun/na adjective and から. The reason why it means “from” instead “therefore” or “because” is because in that sentence から is modifying a noun without it. In that case, it means “from”.
If you wanted to say person X received thing Z because person Y, you would say
If you wanted to say person X received thing Z from person Y, you would say
Keep in mind, it might be somewhat strange to say because person Y, X received Z. I don’t believe it would have the same implication as in English, but I honestly don’t know.
Just my two cents: if you are saying someone received/didn’t receive something from someone else, using から is much more clear than using に. From what I have been taught, Japanese people generally use から in that case as well.
That… doesn’t quite sound right to me, though I’m not sure why. If X/Y are both people, I’d expect this:
田中は山村だから本をもらう vs 田中は山村(のせい/おかげ)で本をもらう
(However, "X receives Z from Y’ would be 田中は山村から本をもらう’)
But, if Y is not a person, this works for me:
Anybody around with a better grasp on grammar who can say check the validity of both when Y is a person?
This means ‘Tanaka receives (a) book(s) from Yamamura’. The から here is a particle that denotes movement from point A to point B. That’s really what it does - when person goes from Point A to Point B and you want to emphasise their starting location (“I went to school from my friend’s house”), you use noun+から. The reason から is used with 手紙 is because it’s emphasising that not only Mai (and not Mary! Read over the kana carefully) got a letter from Mary. Mai could’ve received other letters, but none of them were from Mary.
In my opinion this is ungrammatical. It means something like ‘Because Tanaka is Yamamura, [he] receives (a) book(s)’. It might work if a person has multiple names/personalities (like ‘because Youko is a Nakajima, she is […]’), but I’m not sure if that’s how it would work. The から here denotes reason: Sentence AからSentence B = Because of Sentence A, Sentence B.
The ‘because’ meaning of から only works if there’s a grammatical sentence before it - that’s why there’s だ before the から. So na-adjectives and nouns get a だ, an i-adjective remains as is, and a verb is used in its plain form. (Using the formal forms is grammatical, but is also ridiculously super formal.)