Prima di mandare l’email, rileggo ogni paragrafo e controllo ogni virgola.

In Italian, prima di + infinitive is the normal structure for before doing something.

• prima di mandare l’email = before sending the email

You need di before the infinitive mandare.
A few comparisons:

• Prima di uscire, spengo le luci. = Before going out, I turn off the lights.
• Prima di dormire, leggo. = Before sleeping, I read.

If a full clause follows, Italian often uses prima che instead:

• Prima che mandi l’email, rileggi il testo. = Before you send the email, reread the text.

Yes, both are correct.

• mandare un’email / mandare l’email = to send an email
• inviare un’email / inviare l’email = to send an email

Mandare is very common in everyday speech.
Inviare can sound a little more formal or technical, but it is also extremely normal.

So these are both natural:

• Prima di mandare l’email...
• Prima di inviare l’email...

Because email here takes the singular article la, and before a vowel la becomes l’.

• la email → l’email

This is called elision.

So:

• l’email = the email
• un’email = an email

In modern Italian, email is usually treated as feminine, especially in standard usage, although you may occasionally hear variation.

Italian often drops subject pronouns when they are not needed.

• rileggo already means I reread
• controllo already means I check

The verb ending tells you the subject, so io is often omitted.

So:

• Io rileggo ogni paragrafo = correct, but more emphatic
• Rileggo ogni paragrafo = normal, neutral Italian

This is very common in Italian.

No. Rileggo means I reread or I read again.

It comes from the verb rileggere:

• leggere = to read
• rileggere = to reread

The prefix ri- often gives the idea of again:

• fare = to do
• rifare = to do again, to remake

So in this sentence:

• rileggo ogni paragrafo = I reread every paragraph

Yes. It comes from rileggere, which follows the pattern of leggere.

The io form is:

• io leggo = I read
• io rileggo = I reread

Notice the double g sound in the spelling. This is part of the normal conjugation pattern of leggere and related verbs.

A few forms of rileggere in the present tense:

• io rileggo
• tu rileggi
• lui/lei rilegge
• noi rileggiamo
• voi rileggete
• loro rileggono

Because ogni means each or every, and it is followed by a singular noun in Italian.

So:

• ogni paragrafo = every paragraph
• ogni virgola = every comma

Not:

• ogni paragrafi
• ogni virgole

This is different from some English habits, because English also uses singular after every, but learners sometimes expect a plural idea because the meaning refers to all items individually.

Both can sometimes translate as all or every, but they are used differently.

• ogni + singular noun = every / each
• tutti i + plural noun = all the

Examples:

• Rileggo ogni paragrafo. = I reread every paragraph.
• Rileggo tutti i paragrafi. = I reread all the paragraphs.

In many contexts, both are possible, but the nuance is slightly different:

• ogni focuses on items one by one
• tutti i focuses on the whole set

Because the sentence has two actions with the same subject:

• rileggo ogni paragrafo
• controllo ogni virgola

Italian often links them simply with e = and.

The subject I is understood for both verbs:

• Before sending the email, I reread every paragraph and check every comma.

This is completely natural and very common.

Yes. Virgola means comma.

So:

• controllo ogni virgola = I check every comma

This is a very natural way to say that someone is being careful about punctuation and writing details.

Related punctuation words:

• punto = period / full stop
• punto interrogativo = question mark
• punto esclamativo = exclamation mark

Yes, to some extent. Italian word order is flexible, although some versions sound more natural depending on emphasis.

Original:

• Prima di mandare l’email, rileggo ogni paragrafo e controllo ogni virgola.

You could also say:

• Rileggo ogni paragrafo e controllo ogni virgola prima di mandare l’email.

Both are correct. The original puts the before sending the email idea first, which sets the scene. The second version puts the two actions first and adds the time relation at the end.

Paragrafo is a masculine noun in Italian.

• singular: il paragrafo
• plural: i paragrafi

So:

• ogni paragrafo = every paragraph

This is just the gender and form of the noun; it does not depend on the speaker’s gender.

Yes, that would be understandable, but it is not exactly the same in style.

• rileggo ogni paragrafo is more compact and idiomatic for I reread every paragraph
• leggo ogni paragrafo di nuovo also means I read every paragraph again, but it can sound a little less elegant or less direct here

So your version is possible, but rileggo is the more natural verb choice in this sentence.