N’ignore pas mes messages, s’il te plaît.

Because ne becomes n’ before a vowel sound.

The verb ignorer begins with i-, so French avoids saying ne ignore and shortens it to n’ignore.

This is called elision. You see it a lot in French:

• n’aime pas
• n’oublie pas
• n’écoute pas

So N’ignore pas is just the normal negative form before a vowel.

Because this sentence is in the imperative, the form used for commands and requests.

In French commands, the subject pronoun is usually omitted:

• Ignore mes messages.
• N’ignore pas mes messages.

Even though tu is not written, it is understood. This sentence is speaking to one person informally.

If you wanted to speak:

• to one person formally, or
• to several people,

you would use vous and say:

• N’ignorez pas mes messages, s’il vous plaît.

French negative commands usually use this pattern:

ne / n’ + verb + pas

So here:

• n’ = negative marker
• ignore = the verb
• pas = completes the negation

That gives:

N’ignore pas

This is the standard way to say don’t ignore.

Compare:

• Parle ! = Speak!
• Ne parle pas ! = Don’t speak!

Because this is the tu imperative of an -er verb.

For most regular -er verbs, the tu imperative drops the final -s:

• tu parles → Parle !
• tu regardes → Regarde !
• tu ignores → Ignore !

So in the negative:

• N’ignore pas

That is normal.

A useful extra detail: in some affirmative commands before y or en, the -s comes back:

• Va !
• Vas-y !

But that does not apply here.

Because mes means my with a plural noun.

French possessive adjectives agree with the thing possessed, not with the owner.

So:

• mon message = my message
• mes messages = my messages

Even if there is only one owner, you still use mes because messages is plural.

S’il te plaît is the usual informal way to say please to one person.

Literally, it means something like if it pleases you, but learners should usually think of it simply as please.

It softens the command, so instead of sounding harsh, the sentence becomes more polite or pleading:

• N’ignore pas mes messages. = stronger, more direct
• N’ignore pas mes messages, s’il te plaît. = softer, more polite

Because the sentence uses te, it is informal and directed at one person.

The formal/plural version is:

• s’il vous plaît

The difference is the level of formality and the number of people addressed.

• s’il te plaît = informal, used with tu, usually for one person you know well
• s’il vous plaît = formal, or used for more than one person

So this sentence is clearly addressed to:

• one person
• in an informal way

If you wanted a formal version, you would say:

N’ignorez pas mes messages, s’il vous plaît.

Not exactly.

Ignorer means to ignore, so it suggests deliberately not paying attention to something or someone.

So N’ignore pas mes messages implies something like:

• don’t disregard my messages
• don’t pretend they aren’t there
• don’t leave them unnoticed on purpose

If you specifically wanted to say don’t stop replying or answer me, French might use a different verb, such as:

• Ne réponds pas = don’t reply
• Réponds-moi = reply to me

So ignorer has a stronger sense of deliberate ignoring than simply not responding.

A rough pronunciation guide is:

N’ignore pas mes messages, s’il te plaît.
nee-nyor pah may may-sahzh, seel tuh pleh

A few useful notes:

• N’ignore sounds like nee-nyor
• pas ends with a silent -s
• mes sounds like may
• messages is pronounced roughly may-sahzh
• s’il te plaît sounds like seel tuh pleh

Also, the plural -s in messages is silent, so singular and plural sound the same here:

• message
• messages

Yes.

The core sentence is:

N’ignore pas mes messages.

That is already complete and correct.

Adding s’il te plaît simply makes it sound more polite, softer, or more emotional. Depending on context, leaving it out can sound:

• firmer
• more annoyed
• more direct

So both are correct, but they do not feel exactly the same in tone.