Pour l’entretien de demain, je vais me faire relire le dernier brouillon par Marie avant de l’envoyer en pièce jointe par courriel.

Here pour means for or with a view to. So Pour l’entretien de demain sets the context: this is being done for tomorrow’s interview.

A native English speaker might expect something like For tomorrow’s interview at the end of the sentence, but in French it is very natural to put this kind of context phrase at the beginning.

Also, entretien can mean different things depending on context:

• interview
• meeting
• sometimes even maintenance in other contexts

Here, since the meaning has already been given, it is clearly the interview/meeting sense.

Because le becomes l’ before a vowel sound.

So:

• le entretien → incorrect
• l’entretien → correct

This is called elision. French often drops the final vowel of a short word before another word that begins with a vowel or silent h.

Other examples:

• le ami → l’ami
• je ai → j’ai

Je vais + infinitive is the near future or futur proche. It means I am going to ...

So:

• je vais me faire relire... = I’m going to have ... proofread

French could also use the simple future:

• je me ferai relire...

Both are possible, but je vais + infinitive is very common in everyday speech and often feels more immediate or conversational.

This is the causative construction: faire + infinitive.

It means to have someone do something or to make someone do something, depending on context.

So:

• faire relire = to have [something] reread / proofread

In this sentence:

• je vais me faire relire le dernier brouillon par Marie

means:

• I’m going to have Marie proofread the latest draft for me

Literally, it is something like:

• I am going to make/have reread for myself the latest draft by Marie

French uses faire + infinitive where English often uses have + past participle:

• I had my hair cut → Je me suis fait couper les cheveux
• I’m having Marie proofread it → Je vais me faire relire... par Marie

The me shows that the action is being done for me / to my benefit.

Compare:

• Je vais faire relire le brouillon par Marie.
  = I’m going to have Marie proofread the draft.
• Je vais me faire relire le brouillon par Marie.
  = I’m going to have Marie proofread the draft for me.

This me does not mean that I am the one being reread. It means that I am arranging for this action to happen for my own purposes.

This is a very common pattern in French:

• Je me fais couper les cheveux. = I get my hair cut.
• Je me fais livrer un repas. = I have a meal delivered.

• lire = to read
• relire = to read again

But in many contexts, especially with writing, relire often means to review or to proofread.

So:

• relire un brouillon usually means to read over a draft again carefully, often to check for mistakes or improve it.

That is why relire le dernier brouillon is naturally understood as proofread the latest draft.

Because relire is the infinitive verb, and le dernier brouillon is its direct object.

So the structure is:

• faire relire quelque chose
• to have something proofread

Here:

• le dernier brouillon = the latest draft

French word order is normal here:

• faire relire le dernier brouillon
• have the latest draft proofread

Because Marie is the agent, the person who actually performs the proofreading.

In the causative structure faire + infinitive, the performer of the action is often introduced with par, especially when the thing being acted on is also present.

So:

• faire relire le brouillon par Marie = have the draft proofread by Marie

Using à Marie would not work here in standard French for the meaning by Marie.

A useful way to think of it:

• par + person = by + person, the doer of the infinitive action

Because avant must be followed by de when the next part is an infinitive.

So:

• avant de + infinitive = before doing something

Examples:

• avant de partir = before leaving
• avant de manger = before eating
• avant de l’envoyer = before sending it

So de is required here.

L’ is the direct object pronoun it.

It refers back to le dernier brouillon.

So:

• avant de l’envoyer = before sending it

French uses object pronouns before the infinitive:

• envoyer le brouillon = send the draft
• l’envoyer = send it

En pièce jointe is a fixed expression meaning as an attachment or attached.

So:

• envoyer quelque chose en pièce jointe = to send something as an attachment

Literally:

• pièce jointe = attached document/item

Even though pièce is a noun and jointe looks like an adjective, learners should usually treat en pièce jointe as one expression.

Examples:

• Je vous envoie le document en pièce jointe.
• Vous trouverez le fichier en pièce jointe.

Yes, par courriel means by email.

• courriel is a standard French word for email
• par courriel = by email

Depending on region and register, you may also hear:

• par mail
• par e-mail
• par email

But courriel is often considered more formal or more standard, especially in careful written French.

French often places manner and means expressions after the verb phrase.

Here the final part tells you how the draft will be sent:

• en pièce jointe = as an attachment
• par courriel = by email

So the sequence is:

• first, Marie will proofread the draft
• then, it will be sent as an email attachment

This word order is very natural in French, even if English learners might want to rearrange it.

Yes. The original sentence is natural, but it contains a fairly advanced structure. A simpler version might be:

• Pour l’entretien de demain, Marie va relire le dernier brouillon avant que je l’envoie par courriel en pièce jointe.
• Pour l’entretien de demain, je vais demander à Marie de relire le dernier brouillon avant de l’envoyer par courriel.

These versions are easier to unpack, but the original is more compact and idiomatic because French often uses faire + infinitive to express having someone do something.