Не то чтобы отправитель писал невежливо, но его письмо попало в спам, и я сначала даже не заметила его.

This is a very common Russian pattern for softening or qualifying what you are saying.

Не то чтобы X, но Y means something like:

• It’s not exactly that X; rather, Y
• Not that X, but Y
• I wouldn’t quite say X; the real point is Y

So in this sentence, the speaker is saying:

• the problem was not really that the sender was rude,
• the real issue was that the message went to spam and was missed at first.

This structure often suggests that X is not completely impossible, but it is not the best explanation.

Because писал is the imperfective past tense, and here it fits the idea of manner/style rather than a single completed act.

Compare:

• писал невежливо = was writing in an impolite way / wrote in an impolite manner
• написал would focus more on producing a finished text or writing something specific

In this sentence, the speaker is talking about how the sender came across in the message, not about the mere fact that he completed writing it.

If you used написал, the meaning would shift. For example:

• Не то чтобы отправитель написал что-то невежливое...
  = It’s not that the sender wrote something impolite...

That would sound more like a specific rude wording or phrase.
With писал невежливо, the focus is broader: the sender’s tone or style.

Because невежливо is an adverb, and it modifies the verb писал.

Russian often uses:

• verb + adverb

For example:

• говорить вежливо = to speak politely
• отвечать грубо = to answer rudely
• писать невежливо = to write impolitely / in an impolite way

If you used an adjective such as невежливое, it would need to describe a noun, for example:

• невежливое письмо = an impolite letter

So:

• писал невежливо = the act/style of writing was impolite
• невежливое письмо = the letter itself was impolite

Отправитель means sender.

In email or message contexts, it refers to the person who sent the message. It is in the nominative singular here because it is the subject of писал.

So grammatically:

• отправитель = the sender
• писал = was writing / wrote

Together: the sender wrote

This word is especially natural in technical, email, or formal contexts. In other situations, Russian might also use things like:

• автор письма = the author of the letter
• он = he

But отправитель is very normal when talking about email/messages.

Because the subject is письмо, and письмо is neuter singular.

In the past tense, Russian verbs agree with gender and number:

• masculine: попал
• feminine: попала
• neuter: попало
• plural: попали

So:

• письмо попало в спам = the letter/email ended up in spam

The verb is попасть (perfective), because this is a completed event: the email ended up in the spam folder.

Yes, it is normal, especially in modern everyday Russian, especially in internet or email contexts.

Literally, в спам means into spam, but in real usage it usually means:

• into the spam folder
• marked as spam
• sent to spam

More explicit versions are also possible:

• в папку Спам
• в спам-фильтр (less common in this exact context)

But попасть в спам is a very common practical expression.

Grammatically, в takes the accusative here because it shows movement/result:

• в спам

Since спам is inanimate masculine, its accusative looks like the nominative.

Here и means and and connects another clause:

• его письмо попало в спам
• я сначала даже не заметила его

So the sentence has this structure:

• Не то чтобы ... , но ... , и ...

In English, it is also natural to say:

• ..., but ..., and I didn’t even notice it at first.

The comma before и is there because it joins a new clause with its own subject and verb:

• я
• не заметила

It adds nuance.

• сначала = at first / initially
• даже = even

So:

• я сначала не заметила его = I didn’t notice it at first
• я сначала даже не заметила его = I didn’t even notice it at first

The word даже strengthens the statement. It suggests that the speaker is emphasizing how easily the email was missed.

So the idea is not just I missed it initially, but more like:

• I actually didn’t even notice it at all at first

Yes. Не заметила shows that the speaker is female.

In the Russian past tense, verbs agree with the speaker’s gender when the subject is я:

• я заметил = I noticed (male speaker)
• я заметила = I noticed (female speaker)

So this sentence tells us that the speaker is a woman.

If a man were saying the same sentence, it would be:

• я сначала даже не заметил его

It is the same form, but it plays two different roles.

1. его письмо
   Here его means his:

   • his letter/email

2. не заметила его
   Here его means it (or grammatically, the direct object):

   • didn’t notice it

So in this sentence:

• the first его refers to the sender: his
• the second его refers to письмо: it

This is very normal in Russian. The form его can mean both:

• his
• him / it (in certain cases)

Context tells you which one is meant.

Also, even though письмо is neuter, the object pronoun is still его in the accusative/genitive pattern for third-person pronouns.

Yes. Russian word order is flexible, and different orders shift the emphasis slightly.

The original:

• я сначала даже не заметила его

puts его at the end, which sounds natural and gives a slight final focus to the thing not noticed.

Another possible order:

• я его сначала даже не заметила

This brings the object earlier and can sound a little more direct.

Both are grammatical. The original version is very natural because его refers back to письмо, which has just been mentioned.

Russian often uses word order to manage:

• what is already known
• what is being emphasized
• what sounds smooth in context

So this is not about right vs. wrong, but about information flow and emphasis.

The commas are there because the sentence contains multiple clauses.

1. Не то чтобы отправитель писал невежливо, но ...
   A comma is needed before но.

2. ..., и я сначала даже не заметила его
   Another comma is used before и because a new clause begins, with its own subject and verb:

   • я
   • не заметила

So the sentence is divided like this:

• Не то чтобы отправитель писал невежливо,
• но его письмо попало в спам,
• и я сначала даже не заметила его.

This punctuation is standard Russian punctuation for coordinated clauses.