################# Send email when the password account will expire #################

####################################################################################
############################## Custom variables ###################################
####################################################################################
# Set threshold in days
$ThresholdTrigger=14

#Root OU where find the users
$rootUsersOU='OU=TEDDYCORP,DC=teddycorp,DC=lab'

# SMTP conf
$SMTPServer="smtp.teddycorp.lab"
$eMailSender="system@teddycorp.lab"
$eMailSubjectWarning="Expiration Password"

#eMail Template
$MailTemplateWarning=@"
Bonjour %GivenName%,

Le mot de passe du compte : %Account%
Expire dans moins de %ThresholdTrigger% jours, date d'expiration : %dateExpiration%

Pensez a le changer.

Cordialement
"@

####################################################################################
####################################################################################
####################################################################################

### Init /Set var ###

$ResultUserInfos=@()

### Module and third-party import ###
Import-Module ActiveDirectory


### MAIN ###
#Collect infos utilisateurs (user enable) :
$LstUsers = Get-ADUser -SearchBase $rootUsersOU -Filter 'enabled -eq "true"' -SearchScope Subtree -Properties mail, pwdLastSet | Select-Object *


#Format data and select user with emaim address and expiration time <
foreach($User in $LstUsers){

    #If PSO or GPO
    If($(Get-ADuser $User.SamAccountName -Properties "msDS-ResultantPSO")."msDS-ResultantPSO" -eq $null){
        $DateExpiration=$([datetime]::FromFileTime($User.'msDS-UserPasswordExpiryTimeComputed'))
    }else{
        $DateLastPwdSet=$([datetime]::FromFileTime($User.'pwdLastSet'))
        $PSOPwdDuration=[int]$(Get-ADUserResultantPasswordPolicy -Identity $User.SamAccountName).MaxPasswordAge.days
        $DateExpiration=$DateLastPwdSet.AddDays($PSOPwdDuration)
    }


    #Calcul limit date
    $DateWithExpirationDuration=(Get-Date).AddDays($ThresholdTrigger)


    if(![string]::IsNullOrEmpty($User.mail)){
        if($DateExpiration -lt $DateWithExpirationDuration){
            $ObjectUser = New-Object System.Object
            $ObjectUser | Add-Member -Type NoteProperty -Name ExpirationDate -Value $DateExpiration
            $ObjectUser | Add-Member -Type NoteProperty -Name GivenName -Value $User.GivenName
            $ObjectUser | Add-Member -Type NoteProperty -Name Surname -Value $User.Surname
            $ObjectUser | Add-Member -Type NoteProperty -Name eMailAddress -Value $User.mail
            $ObjectUser | Add-Member -Type NoteProperty -Name UPN -Value $User.UserPrincipalName

            $ResultUserInfos+=$ObjectUser
        }
    }
}


#Write and send eMail :
foreach($UserInfos in $ResultUserInfos){
    $EmailUser=$MailTemplateWarning
    $EmailUser=$EmailUser.Replace("%GivenName%",$UserInfos.GivenName)
    $EmailUser=$EmailUser.Replace("%Account%",$UserInfos.UPN)
    $EmailUser=$EmailUser.Replace("%ThresholdTrigger%",$ThresholdTrigger)
    $EmailUser=$EmailUser.Replace("%dateExpiration%",$UserInfos.ExpirationDate)

    Send-MailMessage -From $eMailSender -To $UserInfos.eMailAddress -Subject $eMailSubjectWarning -Body $EmailUser -SmtpServer $SMTPServer
}