UsersAndGroups.ps1

$TenantId="YOUR_TENANT_ID"
$ClientId="YOUR_CLIENT_ID"
$CertThumbprint="YOUR_CERTIFICATE_THUMBPRINT"
$AdminMail="ADMIN_MAIL"

# Consent to permissions using app created in the last demo.
$AdminConsentUrl="https://login.microsoftonline.com/$TenantId/adminconsent?client_id=$ClientId"
Write-Host-ForeGroundColor Yellow "Please go to the following URL in your browser to provide admin consent"
Write-Host$AdminConsentUrl
Write-Host"Press any key to continue when done ....."
$Key=$host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")

# Authenticate as a confidential client for app only calls.
Connect-Graph-ClientId $ClientId-TenantId $TenantId-CertificateThumbprint $CertThumbprint

# Get group named 'Weekday Employees'
$WeekdayEmployeesGroup=Get-MgGroup-Filter "DisplayName eq 'Weekday Employees'"

# Get Members of the group.
$GroupMembers=Get-MgGroupMember-GroupId $WeekdayEmployeesGroup.Id
$ToRecipients=@()
foreach ($memberin$GroupMembers) {
$User=Get-MgUser-UserId $member.Id-Select "displayName","mail","mailboxSettings"|`
 Select DisplayName, Mail, MailboxSettings

# Get users with invalid workdays in their mailbox setting.
if ( $User.MailboxSettings.WorkingHours.DaysOfWeek-contains"saturday" || `
$User.MailboxSettings.WorkingHours.DaysOfWeek-contains"sunday" ) {
Write-Host-ForegroundColor Yellow "User "$User.DisplayName" has an invalid workday."

$ToRecipients+=@{ 
emailAddress=@{
name=$User.DisplayName;
address=$User.Mail
 }}
 }
}

if ($ToRecipients.Length) {
# Compose message.
$Message=@{
subject="Update Your Mailbox Settings!";
toRecipients=$ToRecipients;
body=@{
contentType="Text";
content="Please update to your mailbox settings to reflect your working hours."+`
" You currently have Saturday and/or Sunday set as workday."
 }
 }

$Admin=Get-MgUser-UserId $AdminMail

# Send mail to users with invalid workdays.
Send-MgUserMail-UserId $Admin.Id-BodyParameter @{message=$Message}
Write-Host-ForegroundColor Green "Mail sent to affected users."
}

Disconnect-Graph