Получатель сказал, что спам иногда попадает даже в папку «Входящие».

Because получатель is the subject of the main clause, so it is in the nominative case.

• Получатель сказал = The recipient said
• The person doing the action of сказал is the subject, so nominative is required.

If it were an object, you would expect another case, for example:

• Я вижу получателя = I see the recipient (accusative)

Сказал is the past tense masculine singular form of сказать.

Russian past tense agrees with the subject in gender and number:

• он / получатель сказал = masculine
• она сказала = feminine
• оно сказало = neuter
• они сказали = plural

Since получатель is a masculine noun, the verb is сказал.

Что introduces a subordinate clause and here means that:

• Получатель сказал, что... = The recipient said that...

This is a very common pattern in Russian:

• Я знаю, что он дома. = I know that he is home.
• Она сказала, что придёт позже. = She said that she would come later.

In English, that is often optional, but in Russian что is usually stated explicitly.

Because спам is the subject of the subordinate clause:

• что спам иногда попадает...
• Literally: that spam sometimes lands/gets...

The thing performing the action of попадает is спам, so it stays in the nominative.

Попадать / попасть often means to get into, to end up in, or to land in a place, not just to fall physically.

So:

• спам попадает в папку = spam ends up in the folder / gets into the folder

By contrast:

• падать = to fall
• попадать = to get into / end up in / reach by chance or by process

In this sentence, the idea is not that spam is physically falling. It is that spam is being sorted or routed into a folder.

Попадает is the imperfective present-tense form of попадать.

That makes sense because the sentence describes something that happens sometimes, as a repeated or general occurrence:

• иногда попадает = sometimes ends up / sometimes gets

If you used the perfective попадёт or past perfective попал, the meaning would be more about one completed event:

• Спам попал в папку. = The spam ended up in the folder.
• Спам иногда попадает... = Spam sometimes ends up...

So the imperfective is the natural choice for habitual or recurring actions.

Because иногда is an adverb meaning sometimes, and it modifies the verb попадает.

Russian word order is flexible, but this placement is very natural:

• спам иногда попадает... = spam sometimes ends up...

You could also move it for emphasis:

• Иногда спам попадает даже в папку «Входящие».
• Спам попадает иногда даже в папку «Входящие».

But the original order is the most neutral and smooth.

Because after в, Russian uses different cases depending on whether you mean movement into something or location inside something.

• в + accusative = motion into / to
• в + prepositional = location in / inside

Here:

• в папку uses the accusative
• because попадает в папку means gets into the folder / ends up in the folder

Compare:

• Письмо попадает в папку. = The message goes into the folder.
• Письмо лежит в папке. = The message is in the folder.

So в папку focuses on entering the folder, not simply being there.

Because папка is a feminine noun, and in the accusative singular it changes to папку.

This is a very common pattern for feminine nouns ending in -а:

• папка → папку
• книга → книгу
• машина → машину

So after в with the meaning of motion into, you get:

• в папку

Даже means even and adds emphasis.

• даже в папку «Входящие» = even into the Inbox folder

The idea is that this is somewhat surprising: spam can end up not only in spam/junk folders, but even in the inbox.

Its position is important:

• даже в папку «Входящие» emphasizes the destination
• it highlights Inbox as the unexpected place

Входящие is the standard interface label for Inbox, and it is historically/grammatically a plural form meaning something like incoming ones or incoming messages.

It comes from the adjective входящий = incoming. In email interfaces, Russian often uses adjective forms as nouns:

• Входящие = Inbox (literally, incoming [messages])
• Исходящие = Outbox / sent outgoing items

So even though English uses the singular Inbox, Russian commonly uses the plural label Входящие.

Because it is the name of a folder/interface label.

In Russian, names of folders, buttons, menu items, and titles are often put in quotation marks, especially in normal running text:

• папка «Входящие»
• кнопка «Отправить»
• меню «Файл»

Russian typically uses angle quotes:

• « »

These are standard Russian quotation marks.

Yes. Russian word order is flexible, and the sentence could be rearranged without changing the basic meaning. For example:

• Получатель сказал, что иногда спам попадает даже в папку «Входящие».
• Получатель сказал, что даже в папку «Входящие» спам иногда попадает.

However, different word orders shift the emphasis slightly. The original version is natural and neutral:

• Получатель сказал, что спам иногда попадает даже в папку «Входящие».

It presents the information in a straightforward way: subject → frequency → verb → emphasized destination.

Yes, and recipient is usually the better translation in this context.

Получатель can mean:

• recipient
• receiver

But in email, messages, parcels, documents, and similar contexts, recipient sounds more natural in English:

• получатель письма = recipient of the message
• получатель посылки = recipient of the package

So Получатель сказал... is best understood as The recipient said... in this sentence.