اليوم عندي بريد من البنك.

A careful fully-vowelled reading is:

الْيَوْمَ عِنْدِي بَرِيدٌ مِنَ الْبَنْكِ

A rough transliteration is:

al-yawma ʿindī barīdun mina l-banki

In normal pausing speech, the case endings are often not pronounced, so it may sound more like:

al-yawm ʿindī barīd min al-bank

Two pronunciation notes:

• ع in عندي is a deep throat sound with no exact English equivalent.
• بريد has a long ī sound: ba-REED.

In Arabic, possession is often expressed without a verb like English have.

So instead of saying something like I have mail, Arabic says something closer to:

At me there is mail

That is exactly what عندي بريد means:

• عندي = with me / at me
• بريد = mail

This is a very common Arabic pattern.

عندي is made of two parts:

• عند = at, with, in the possession of
• ي = my / me

So عندي literally means at me or with me, and in natural English it often means I have.

You will see the same pattern with other pronouns:

• عندك = you have
• عنده = he has
• عندها = she has
• عندنا = we have

اليوم means today, and Arabic often places time expressions near the beginning of the sentence.

So:

اليوم عندي بريد من البنك

naturally means:

Today, I have mail from the bank.

Starting with اليوم gives a clear time frame right away. Arabic word order is flexible, so you could move it, but putting it first is very normal.

No. اليوم is not the subject. It is a time expression, functioning like today in English.

The sentence is really built around:

• عندي بريد = I have mail

And اليوم just adds when this is true:

• today

So it is better to think of اليوم as an adverbial expression of time, not the subject.

بريد usually means mail, post, or postal correspondence.

In this sentence, it most naturally means:

• mail from the bank
• possibly a letter or official correspondence from the bank

It is a general word, not necessarily just one physical letter. If you wanted to be more specific, you could say:

• رسالة = a letter/message
• بريد إلكتروني = email

So بريد here is a broad, natural word for mail/post.

من means from.

So:

• من البنك = from the bank

It tells you the source of the mail.

This is very straightforward:

• بريد من البنك = mail from the bank
• رسالة من البنك = a letter from the bank

Also, after a preposition like من, the following noun is in the genitive case, which is why the fully-vowelled form is البنكِ.

ال is the definite article, meaning the.

So:

• البنك = the bank
• بنك = a bank

In this sentence, البنك suggests a specific bank, probably one already known from context, such as my bank or the bank we are talking about.

English often says the bank in this kind of situation too, so the Arabic matches that nicely.

Because the sentence is talking about some mail, not the mail as a specific already-known item.

So:

• بريد = mail / some mail
• البريد = the mail

In many contexts, بريد behaves a bit like an uncountable noun in English, similar to mail. English also often says:

• I have mail not
• I have the mail

So the indefiniteness here is very natural.

In careful formal Arabic, the sentence can be read as:

الْيَوْمَ عِنْدِي بَرِيدٌ مِنَ الْبَنْكِ

Here is why:

• اليومَ: often accusative as an adverbial expression of time
• بريدٌ: nominative, because it is the main noun in the predicate structure
• البنكِ: genitive, because it comes after من

In everyday reading and speaking, especially when pausing, many speakers do not pronounce these final endings clearly, so learners often first meet the sentence as:

اليوم عندي بريد من البنك

Yes. لديّ بريد من البنك is also correct and means the same thing.

Both عندي and لديّ can express I have.

A useful general difference:

• عندي is very common and natural
• لديّ often sounds a bit more formal or written

So in Modern Standard Arabic, both are fine, but لديّ may feel slightly more formal in style.

Yes, Arabic word order is flexible.

For example, you could say:

• عندي بريد من البنك اليوم
• بريد من البنك عندي اليوم

But these versions may shift the emphasis a little.

The original:

• اليوم عندي بريد من البنك puts focus on today

That makes it a very natural choice if the time is important or new information.

Yes. If you say:

عندي رسالة من البنك

that means I have a letter/message from the bank.

Compared with that:

• بريد is more general: mail, post, correspondence
• رسالة is more specific: a letter or message

So if the original sentence is about receiving mail in general, بريد is appropriate. If you mean one letter in particular, رسالة may be better.