Tiens Adrien, petite fonction pour déclarer un envoi de mail:
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Function Envoi-Email {
    Param (
        [Parameter(`
            Mandatory=$true)]
        [String]$EmailTo,
        [Parameter(`
            Mandatory=$true)]
        [String]$Subject,
        [Parameter(`
            Mandatory=$true)]
        [String]$Body,
        [Parameter(`
            Mandatory=$true)]
        [String]$EmailFrom="myself@gmail.com",  #This gives a default value to the $EmailFrom command
        [Parameter(`
            mandatory=$false)]
        [String]$attachment,
        [Parameter(`
            mandatory=$true)]
        [String]$Password
    )

        $SMTPServer = "smtp.gmail.com"
        $SMTPMessage = New-Object System.Net.Mail.MailMessage($EmailFrom,$EmailTo,$Subject,$Body)
        if ($attachment -ne $null) {
            $SMTPattachment = New-Object System.Net.Mail.Attachment($attachment)
            $SMTPMessage.Attachments.Add($SMTPattachment)
        }
        $SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587)
        $SMTPClient.EnableSsl = $true
        $SMTPClient.Credentials = New-Object System.Net.NetworkCredential($EmailFrom.Split("@")[0], $Password);
        $SMTPClient.Send($SMTPMessage)
        Remove-Variable -Name SMTPClient
        Remove-Variable -Name Password

}

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Ensuite pour utiliser ta fonction:
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Envoi-Email -EmailTo "Myself@gmail.com" -Body "Test Body" -Subject "Test Subject" -attachment "C:\cdf.pdf" -password "Passowrd"