Remove Duplicates from Excel

[Pushkraj19]

I searched about this on the internet everywhere no luck.

The question is how can I make sure to avoid duplicates to my mailing list. Where the email needs to be unique but the list_id should be the same cause it's the id of that mailing list where the email is inserted.

I tried validation didn't work. I tried rule didn't work :( also, the part issue is row guessing I don't know how to use row guess in excel validation so I used a single row and uploaded a single row with email as an excel column and email as a row validation but it didn't work.

I also tried model validation inside the model(array $row) but when I count for presence email it always gives me zero it only starts to count once the data is inserted into the database.

my current code is

class EmailsImport implements ToModel, SkipsEmptyRows, WithHeadingRow, WithBatchInserts, WithChunkReading, WithEvents, ShouldQueue, SkipsOnFailure
{
    use Importable, RegistersEventListeners, SkipsFailures;

    public $list_id;

    public function  __construct($list_id)
    {
        $this->list_id = $list_id;
    }

    /**
     * @param array $row
     *
     * @return \Illuminate\Database\Eloquent\Model|null
     */
    public function model(array $row)
    {
        return new Email([
            'email'  => $this->sanatize($row["email"] ?? $row["emails"]),
            'list_id'   => $this->list_id,
        ]);
    }

    public function sanatize($var)
    {
        return strtolower(preg_replace('/[ \s*]*/', '', trim($var)));
    }

    public function batchSize(): int
    {
        return 1000;
    }

    public function chunkSize(): int
    {
        return 5000;
    }

}

I thought about creating a table email as unique but how can I do it when the 2 list_id can have the same email.

Please someone help me.