Оргкомитет отправил раздаточные материалы по почте.

Оргкомитет is short for организационный комитет — the organizing committee.

It is a very common Russian abbreviation formed by combining parts of words:

• орг- from организационный
• комитет = committee

Russian often makes compact official-style words like this. Even though it is shortened, it behaves like a normal noun.

Отправил is the past tense, masculine singular form of отправить (to send).

It matches the subject оргкомитет, which is:

• singular
• grammatically masculine

So:

• оргкомитет отправил = the organizing committee sent

Compare:

• комиссия отправила = the commission sent
• люди отправили = the people sent

This is a question of aspect.

• отправить = perfective → focuses on a completed action
• отправлять = imperfective → focuses on process, repetition, or background action

In this sentence, the idea is that the committee sent the materials as a completed event, so отправил is natural.

Compare:

• Оргкомитет отправил материалы по почте. = The committee sent the materials by mail.
• Оргкомитет отправлял материалы по почте. = The committee was sending / used to send the materials by mail.

Because this phrase usually means handout materials, handouts, or distributed materials, which are naturally thought of as a set of items rather than one single thing.

• раздаточный материал = handout material / a handout item
• раздаточные материалы = handout materials / handouts

In many contexts, Russian prefers the plural here just like English often says handouts.

It means something like:

• handouts
• printed materials given out to participants
• informational materials for distribution

The adjective раздаточные comes from раздать / раздавать = to hand out, distribute.

So literally it is something like materials for handing out.

They are in the accusative plural because they are the direct object of отправил.

The committee sent what?

• раздаточные материалы

For inanimate plural nouns, the accusative is usually the same as the nominative:

• nominative: раздаточные материалы
• accusative: раздаточные материалы

So the form does not visibly change here, but its function is accusative.

По почте is a very common expression meaning:

• by mail
• through the mail
• by post

Here почте is the form used after по in this expression.

So:

• отправить по почте = to send by mail

This is one of the standard ways to express the method of sending something.

Yes. Отправить почтой is also possible and means nearly the same thing.

But:

• по почте is very common and idiomatic
• почтой can sound slightly more formal or more like emphasizing the means

So both are correct:

• отправил по почте
• отправил почтой

For a learner, по почте is an excellent standard phrase to remember.

Russian has no articles.

So Russian does not normally use words equivalent to the or a/an. The listener understands from context whether something is:

• specific
• general
• already known
• new information

So:

• Оргкомитет can mean the organizing committee
• раздаточные материалы can mean the handout materials or simply handout materials

English must choose an article, but Russian does not.

Yes. Russian word order is much more flexible than English word order because case endings show grammatical roles.

The neutral version here is:

• Оргкомитет отправил раздаточные материалы по почте.

But other orders are possible, for example:

• Раздаточные материалы оргкомитет отправил по почте.
• По почте оргкомитет отправил раздаточные материалы.

These variants may shift the emphasis:

• what was sent
• who sent it
• how it was sent

But the basic meaning stays the same.

You could say раздаточный материал, but the meaning changes slightly.

• раздаточный материал = handout material, handout matter, a handout item
• раздаточные материалы = handouts, handout materials, a set of distributed documents

In real-life situations such as conferences, seminars, or events, the plural раздаточные материалы is especially common because there are often multiple pages or items.

Russian nouns often have grammatical gender, and комитет is masculine. Since оргкомитет is built around комитет, it is also masculine.

That is why the past tense verb is:

• отправил masculine not
• отправила feminine
• отправило neuter

So even though a committee is a group of people, grammatically it is treated as a single masculine noun.

Yes, it is completely natural.

It sounds like a normal formal or administrative sentence, especially in contexts like:

• conferences
• seminars
• events
• official correspondence

The vocabulary is slightly formal because of words like:

• оргкомитет
• раздаточные материалы

But in context, it sounds very normal and idiomatic.